261859500 has 384 divisors, whose sum is σ = 1031546880. Its totient is φ = 55987200.

The previous prime is 261859469. The next prime is 261859537. The reversal of 261859500 is 5958162.

It is a happy number.

261859500 is a `hidden beast` number, since 2 + 61 + 8 + 595 + 0 + 0 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1606419 + ... + 1606581.

It is an arithmetic number, because the mean of its divisors is an integer number (2686320).

Almost surely, 2^261859500 is an apocalyptic number.

261859500 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 261859500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (515773440).

261859500 is an abundant number, since it is smaller than the sum of its proper divisors (769687380).

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

261859500 is a wasteful number, since it uses less digits than its factorization.

261859500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215 (or 197 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 261859500 is about 16182.0734147389. The cubic root of 261859500 is about 639.7683894996.

The spelling of 261859500 in words is "two hundred sixty-one million, eight hundred fifty-nine thousand, five hundred".