51131797 has 4 divisors (see below), whose sum is σ = 52378956. Its totient is φ = 49884640.

The previous prime is 51131777. The next prime is 51131837. The reversal of 51131797 is 79713115.

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

It can be written as a sum of positive squares in 2 ways, for example, as 8608356 + 42523441 = 2934^2 + 6521^2 .

It is a cyclic number.

It is not a de Polignac number, because 51131797 - 2¹⁹ = 50607509 is a prime.

It is a super-2 number, since 2×51131797² = 5228921328898418, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51131747) 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, 623518 + ... + 623599.

It is an arithmetic number, because the mean of its divisors is an integer number (13094739).

Almost surely, 2^51131797 is an apocalyptic number.

It is an amenable number.

51131797 is a deficient number, since it is larger than the sum of its proper divisors (1247159).

51131797 is a wasteful number, since it uses less digits than its factorization.

51131797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1247158.

The product of its digits is 6615, while the sum is 34.

The square root of 51131797 is about 7150.6501103047. The cubic root of 51131797 is about 371.1621530671.

The spelling of 51131797 in words is "fifty-one million, one hundred thirty-one thousand, seven hundred ninety-seven".