261657136410722 has 32 divisors (see below), whose sum is σ = 423952449560640. Its totient is φ = 120400669955520.

The previous prime is 261657136410661. The next prime is 261657136410767. The reversal of 261657136410722 is 227014631756162.

It is a super-2 number, since 2×261657136410722² (a number of 30 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16918697 + ... + 28452707.

It is an arithmetic number, because the mean of its divisors is an integer number (13248514048770).

Almost surely, 2^{261657136410722} is an apocalyptic number.

261657136410722 is a deficient number, since it is larger than the sum of its proper divisors (162295313149918).

261657136410722 is a wasteful number, since it uses less digits than its factorization.

261657136410722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11536658.

The product of its (nonzero) digits is 5080320, while the sum is 53.

The spelling of 261657136410722 in words is "two hundred sixty-one trillion, six hundred fifty-seven billion, one hundred thirty-six million, four hundred ten thousand, seven hundred twenty-two".