51640436 has 6 divisors (see below), whose sum is σ = 90370770. Its totient is φ = 25820216.

The previous prime is 51640429. The next prime is 51640481. The reversal of 51640436 is 63404615.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 42902500 + 8737936 = 6550^2 + 2956^2 .

It is a junction number, because it is equal to n+sod(n) for n = 51640399 and 51640408.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6455051 + ... + 6455058.

It is an arithmetic number, because the mean of its divisors is an integer number (15061795).

Almost surely, 2^51640436 is an apocalyptic number.

It is an amenable number.

51640436 is a deficient number, since it is larger than the sum of its proper divisors (38730334).

51640436 is a wasteful number, since it uses less digits than its factorization.

51640436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12910113 (or 12910111 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 51640436 is about 7186.1280255782. The cubic root of 51640436 is about 372.3888195736.

The spelling of 51640436 in words is "fifty-one million, six hundred forty thousand, four hundred thirty-six".