261887976630 has 64 divisors (see below), whose sum is σ = 798134791680. Its totient is φ = 59860108512.

The previous prime is 261887976613. The next prime is 261887976631. The reversal of 261887976630 is 36679788162.

261887976630 is a `hidden beast` number, since 2 + 618 + 8 + 7 + 9 + 7 + 6 + 6 + 3 + 0 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261887976631) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 69280644 + ... + 69284423.

It is an arithmetic number, because the mean of its divisors is an integer number (12470856120).

Almost surely, 2^261887976630 is an apocalyptic number.

261887976630 is an abundant number, since it is smaller than the sum of its proper divisors (536246815050).

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

261887976630 is a wasteful number, since it uses less digits than its factorization.

261887976630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138565090 (or 138565084 counting only the distinct ones).

The product of its (nonzero) digits is 36578304, while the sum is 63.

The spelling of 261887976630 in words is "two hundred sixty-one billion, eight hundred eighty-seven million, nine hundred seventy-six thousand, six hundred thirty".