261423244641 has 32 divisors (see below), whose sum is σ = 395179223040. Its totient is φ = 152391115584.

The previous prime is 261423244637. The next prime is 261423244651. The reversal of 261423244641 is 146442324162.

It is not a de Polignac number, because 261423244641 - 2² = 261423244637 is a prime.

It is a super-2 number, since 2×261423244641² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 261423244641.

It is not an unprimeable number, because it can be changed into a prime (261423244631) 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, 9268426 + ... + 9296588.

It is an arithmetic number, because the mean of its divisors is an integer number (12349350720).

Almost surely, 2^261423244641 is an apocalyptic number.

It is an amenable number.

261423244641 is a deficient number, since it is larger than the sum of its proper divisors (133755978399).

261423244641 is a wasteful number, since it uses less digits than its factorization.

261423244641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40725.

The product of its digits is 221184, while the sum is 39.

The spelling of 261423244641 in words is "two hundred sixty-one billion, four hundred twenty-three million, two hundred forty-four thousand, six hundred forty-one".