261642351 has 8 divisors (see below), whose sum is σ = 352243840. Its totient is φ = 172734552.

The previous prime is 261642349. The next prime is 261642371. The reversal of 261642351 is 153246162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 261642351 - 2¹ = 261642349 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261642301) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 423061 + ... + 423678.

It is an arithmetic number, because the mean of its divisors is an integer number (44030480).

Almost surely, 2^261642351 is an apocalyptic number.

261642351 is a deficient number, since it is larger than the sum of its proper divisors (90601489).

261642351 is a wasteful number, since it uses less digits than its factorization.

261642351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 846845.

The product of its digits is 8640, while the sum is 30.

The square root of 261642351 is about 16175.3624688908. The cubic root of 261642351 is about 639.5914963116.

The spelling of 261642351 in words is "two hundred sixty-one million, six hundred forty-two thousand, three hundred fifty-one".