51601661111 has 32 divisors (see below), whose sum is σ = 69588868608. Its totient is φ = 36952410240.

The previous prime is 51601661071. The next prime is 51601661113. The reversal of 51601661111 is 11116610615.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 51601661111 - 2²² = 51597466807 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51601661113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 113681 + ... + 340773.

It is an arithmetic number, because the mean of its divisors is an integer number (2174652144).

Almost surely, 2^51601661111 is an apocalyptic number.

51601661111 is a deficient number, since it is larger than the sum of its proper divisors (17987207497).

51601661111 is a wasteful number, since it uses less digits than its factorization.

51601661111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227351.

The product of its (nonzero) digits is 1080, while the sum is 29.

The spelling of 51601661111 in words is "fifty-one billion, six hundred one million, six hundred sixty-one thousand, one hundred eleven".