51516481 has 4 divisors (see below), whose sum is σ = 53756352. Its totient is φ = 49276612.

The previous prime is 51516473. The next prime is 51516497. The reversal of 51516481 is 18461515.

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.

It is a cyclic number.

It is not a de Polignac number, because 51516481 - 2³ = 51516473 is a prime.

It is a super-2 number, since 2×51516481² = 5307895629246722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51516431) 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, 1119901 + ... + 1119946.

It is an arithmetic number, because the mean of its divisors is an integer number (13439088).

Almost surely, 2^51516481 is an apocalyptic number.

It is an amenable number.

51516481 is a deficient number, since it is larger than the sum of its proper divisors (2239871).

51516481 is a wasteful number, since it uses less digits than its factorization.

51516481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2239870.

The product of its digits is 4800, while the sum is 31.

The square root of 51516481 is about 7177.4982410308. The cubic root of 51516481 is about 372.0906266460.

Adding to 51516481 its reverse (18461515), we get a palindrome (69977996).

The spelling of 51516481 in words is "fifty-one million, five hundred sixteen thousand, four hundred eighty-one".