51777621 has 24 divisors (see below), whose sum is σ = 86284224. Its totient is φ = 29306880.

The previous prime is 51777613. The next prime is 51777653. The reversal of 51777621 is 12677715.

It is not a de Polignac number, because 51777621 - 2³ = 51777613 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51777601) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2901 + ... + 10581.

It is an arithmetic number, because the mean of its divisors is an integer number (3595176).

Almost surely, 2^51777621 is an apocalyptic number.

It is an amenable number.

51777621 is a deficient number, since it is larger than the sum of its proper divisors (34506603).

51777621 is a wasteful number, since it uses less digits than its factorization.

51777621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7801 (or 7798 counting only the distinct ones).

The product of its digits is 20580, while the sum is 36.

The square root of 51777621 is about 7195.6668210806. Note that the first 3 decimals coincide. The cubic root of 51777621 is about 372.7182835447.

The spelling of 51777621 in words is "fifty-one million, seven hundred seventy-seven thousand, six hundred twenty-one".