51491745 has 12 divisors (see below), whose sum is σ = 89252436. Its totient is φ = 27462240.

The previous prime is 51491731. The next prime is 51491773. The reversal of 51491745 is 54719415.

It can be written as a sum of positive squares in 2 ways, for example, as 27373824 + 24117921 = 5232^2 + 4911^2 .

It is not a de Polignac number, because 51491745 - 2⁶ = 51491681 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 572086 + ... + 572175.

It is an arithmetic number, because the mean of its divisors is an integer number (7437703).

Almost surely, 2^51491745 is an apocalyptic number.

It is an amenable number.

51491745 is a deficient number, since it is larger than the sum of its proper divisors (37760691).

51491745 is a wasteful number, since it uses less digits than its factorization.

51491745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1144272 (or 1144269 counting only the distinct ones).

The product of its digits is 25200, while the sum is 36.

The square root of 51491745 is about 7175.7748710505. The cubic root of 51491745 is about 372.0310631362.

The spelling of 51491745 in words is "fifty-one million, four hundred ninety-one thousand, seven hundred forty-five".