261520016431 has 16 divisors (see below), whose sum is σ = 273440378880. Its totient is φ = 249646003200.

The previous prime is 261520016411. The next prime is 261520016447. The reversal of 261520016431 is 134610025162.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 261520016431 - 2⁵ = 261520016399 is a prime.

It is a super-2 number, since 2×261520016431² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261520016393 and 261520016402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261520016411) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27234031 + ... + 27243631.

It is an arithmetic number, because the mean of its divisors is an integer number (17090023680).

Almost surely, 2^261520016431 is an apocalyptic number.

261520016431 is a deficient number, since it is larger than the sum of its proper divisors (11920362449).

261520016431 is a wasteful number, since it uses less digits than its factorization.

261520016431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11886.

The product of its (nonzero) digits is 8640, while the sum is 31.

The spelling of 261520016431 in words is "two hundred sixty-one billion, five hundred twenty million, sixteen thousand, four hundred thirty-one".