51637994 has 4 divisors (see below), whose sum is σ = 77456994. Its totient is φ = 25818996.

The previous prime is 51637961. The next prime is 51637997. The reversal of 51637994 is 49973615.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 38278969 + 13359025 = 6187^2 + 3655^2 .

It is not an unprimeable number, because it can be changed into a prime (51637997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12909497 + ... + 12909500.

Almost surely, 2^51637994 is an apocalyptic number.

51637994 is a deficient number, since it is larger than the sum of its proper divisors (25819000).

51637994 is a wasteful number, since it uses less digits than its factorization.

51637994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25818999.

The product of its digits is 204120, while the sum is 44.

The square root of 51637994 is about 7185.9581128754. The cubic root of 51637994 is about 372.3829495751.

The spelling of 51637994 in words is "fifty-one million, six hundred thirty-seven thousand, nine hundred ninety-four".