51231634152661 has 4 divisors (see below), whose sum is σ = 51231710900524. Its totient is φ = 51231557404800.

The previous prime is 51231634152659. The next prime is 51231634152703. The reversal of 51231634152661 is 16625143613215.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 49927084128100 + 1304550024561 = 7065910^2 + 1142169^2 .

It is a cyclic number.

It is not a de Polignac number, because 51231634152661 - 2¹ = 51231634152659 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 (51231634102661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37363770 + ... + 38710651.

It is an arithmetic number, because the mean of its divisors is an integer number (12807927725131).

Almost surely, 2^{51231634152661} is an apocalyptic number.

It is an amenable number.

51231634152661 is a deficient number, since it is larger than the sum of its proper divisors (76747863).

51231634152661 is an equidigital number, since it uses as much as digits as its factorization.

51231634152661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76747862.

The product of its digits is 777600, while the sum is 46.

Adding to 51231634152661 its reverse (16625143613215), we get a palindrome (67856777765876).

The spelling of 51231634152661 in words is "fifty-one trillion, two hundred thirty-one billion, six hundred thirty-four million, one hundred fifty-two thousand, six hundred sixty-one".