261975420 has 288 divisors, whose sum is σ = 989614080. Its totient is φ = 54743040.

The previous prime is 261975403. The next prime is 261975421. The reversal of 261975420 is 24579162.

261975420 is a `hidden beast` number, since 26 + 1 + 97 + 542 + 0 = 666.

It is a super-2 number, since 2×261975420² = 137262241368352800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261975421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 741964 + ... + 742316.

It is an arithmetic number, because the mean of its divisors is an integer number (3436160).

Almost surely, 2^261975420 is an apocalyptic number.

261975420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261975420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (494807040).

261975420 is an abundant number, since it is smaller than the sum of its proper divisors (727638660).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261975420 is a wasteful number, since it uses less digits than its factorization.

261975420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 425 (or 420 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 261975420 is about 16185.6547596938. The cubic root of 261975420 is about 639.8627798260.

The spelling of 261975420 in words is "two hundred sixty-one million, nine hundred seventy-five thousand, four hundred twenty".