261015651 has 48 divisors (see below), whose sum is σ = 415935520. Its totient is φ = 156764160.

The previous prime is 261015641. The next prime is 261015679. The reversal of 261015651 is 156510162.

It is a happy number.

261015651 is a `hidden beast` number, since 2 + 6 + 1 + 0 + 1 + 5 + 651 = 666.

It is not a de Polignac number, because 261015651 - 2¹⁴ = 260999267 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261015641) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1236936 + ... + 1237146.

Almost surely, 2^261015651 is an apocalyptic number.

261015651 is a deficient number, since it is larger than the sum of its proper divisors (154919869).

261015651 is a wasteful number, since it uses less digits than its factorization.

261015651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 436 (or 433 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 27.

The square root of 261015651 is about 16155.9788004317. The cubic root of 261015651 is about 639.0804265921.

The spelling of 261015651 in words is "two hundred sixty-one million, fifteen thousand, six hundred fifty-one".