51502681 has 4 divisors (see below), whose sum is σ = 53741952. Its totient is φ = 49263412.

The previous prime is 51502667. The next prime is 51502709. The reversal of 51502681 is 18620515.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18620515 = 5 ⋅3724103.

It is a cyclic number.

It is not a de Polignac number, because 51502681 - 2⁹ = 51502169 is a prime.

It is a super-2 number, since 2×51502681² = 5305052300375522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51502651) 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, 1119601 + ... + 1119646.

It is an arithmetic number, because the mean of its divisors is an integer number (13435488).

Almost surely, 2^51502681 is an apocalyptic number.

It is an amenable number.

51502681 is a deficient number, since it is larger than the sum of its proper divisors (2239271).

51502681 is a wasteful number, since it uses less digits than its factorization.

51502681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2239270.

The product of its (nonzero) digits is 2400, while the sum is 28.

The square root of 51502681 is about 7176.5368388938. The cubic root of 51502681 is about 372.0573990321.

The spelling of 51502681 in words is "fifty-one million, five hundred two thousand, six hundred eighty-one".