51644438 has 4 divisors (see below), whose sum is σ = 77466660. Its totient is φ = 25822218.

The previous prime is 51644393. The next prime is 51644441. The reversal of 51644438 is 83444615.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83444615 = 5 ⋅16688923.

It is a junction number, because it is equal to n+sod(n) for n = 51644398 and 51644407.

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, 12911108 + ... + 12911111.

It is an arithmetic number, because the mean of its divisors is an integer number (19366665).

Almost surely, 2^51644438 is an apocalyptic number.

51644438 is a deficient number, since it is larger than the sum of its proper divisors (25822222).

51644438 is a wasteful number, since it uses less digits than its factorization.

51644438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25822221.

The product of its digits is 46080, while the sum is 35.

The square root of 51644438 is about 7186.4064733356. The cubic root of 51644438 is about 372.3984390480.

The spelling of 51644438 in words is "fifty-one million, six hundred forty-four thousand, four hundred thirty-eight".