261774938880 has 864 divisors, whose sum is σ = 1131666192384. Its totient is φ = 54392684544.

The previous prime is 261774938879. The next prime is 261774938881. The reversal of 261774938880 is 88839477162.

261774938880 is a `hidden beast` number, since 2 + 6 + 177 + 4 + 9 + 388 + 80 = 666.

It is an interprime number because it is at equal distance from previous prime (261774938879) and next prime (261774938881).

It is a super-2 number, since 2×261774938880² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (261774938881) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 70235577 + ... + 70239303.

Almost surely, 2^261774938880 is an apocalyptic number.

261774938880 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 261774938880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (565833096192).

261774938880 is an abundant number, since it is smaller than the sum of its proper divisors (869891253504).

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

261774938880 is a wasteful number, since it uses less digits than its factorization.

261774938880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3841 (or 3824 counting only the distinct ones).

The product of its (nonzero) digits is 32514048, while the sum is 63.

The spelling of 261774938880 in words is "two hundred sixty-one billion, seven hundred seventy-four million, nine hundred thirty-eight thousand, eight hundred eighty".