51157749 has 4 divisors (see below), whose sum is σ = 68210336. Its totient is φ = 34105164.

The previous prime is 51157739. The next prime is 51157751. The reversal of 51157749 is 94775115.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 51157749 - 2⁷ = 51157621 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 (51157739) 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, 8526289 + ... + 8526294.

It is an arithmetic number, because the mean of its divisors is an integer number (17052584).

Almost surely, 2^51157749 is an apocalyptic number.

It is an amenable number.

51157749 is a deficient number, since it is larger than the sum of its proper divisors (17052587).

51157749 is a wasteful number, since it uses less digits than its factorization.

51157749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17052586.

The product of its digits is 44100, while the sum is 39.

The square root of 51157749 is about 7152.4645402826. The cubic root of 51157749 is about 371.2249370331.

The spelling of 51157749 in words is "fifty-one million, one hundred fifty-seven thousand, seven hundred forty-nine".