51910609921 has 9 divisors (see below), whose sum is σ = 52668455683. Its totient is φ = 51163525840.

The previous prime is 51910609903. The next prime is 51910609951. The reversal of 51910609921 is 12990601915.

The square root of 51910609921 is 227839.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 29254339521 + 22656270400 = 171039^2 + 150520^2 .

It is not a de Polignac number, because 51910609921 - 2²⁹ = 51373739009 is a prime.

It is a super-2 number, since 2×51910609921² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51910609901) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 16174965 + ... + 16178173.

Almost surely, 2^51910609921 is an apocalyptic number.

51910609921 is the 227839-th square number.

51910609921 is the 113920-th centered octagonal number.

It is an amenable number.

51910609921 is a deficient number, since it is larger than the sum of its proper divisors (757845762).

51910609921 is an frugal number, since it uses more digits than its factorization.

51910609921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6560 (or 3280 counting only the distinct ones).

The product of its (nonzero) digits is 43740, while the sum is 43.

The spelling of 51910609921 in words is "fifty-one billion, nine hundred ten million, six hundred nine thousand, nine hundred twenty-one".