51064639 has 4 divisors (see below), whose sum is σ = 52310160. Its totient is φ = 49819120.

The previous prime is 51064631. The next prime is 51064649. The reversal of 51064639 is 93646015.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93646015 = 5 ⋅18729203.

It is a cyclic number.

It is not a de Polignac number, because 51064639 - 2³ = 51064631 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51064631) 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, 622699 + ... + 622780.

It is an arithmetic number, because the mean of its divisors is an integer number (13077540).

Almost surely, 2^51064639 is an apocalyptic number.

51064639 is a deficient number, since it is larger than the sum of its proper divisors (1245521).

51064639 is a wasteful number, since it uses less digits than its factorization.

51064639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1245520.

The product of its (nonzero) digits is 19440, while the sum is 34.

The square root of 51064639 is about 7145.9526306854. The cubic root of 51064639 is about 370.9995834570. Note that the first 3 decimals are identical.

The spelling of 51064639 in words is "fifty-one million, sixty-four thousand, six hundred thirty-nine".