51691545 has 12 divisors (see below), whose sum is σ = 89598756. Its totient is φ = 27568800.

The previous prime is 51691537. The next prime is 51691559. The reversal of 51691545 is 54519615.

51691545 is a `hidden beast` number, since 51 + 69 + 1 + 545 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 32216976 + 19474569 = 5676^2 + 4413^2 .

It is not a de Polignac number, because 51691545 - 2³ = 51691537 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, 574306 + ... + 574395.

It is an arithmetic number, because the mean of its divisors is an integer number (7466563).

Almost surely, 2^51691545 is an apocalyptic number.

It is an amenable number.

51691545 is a deficient number, since it is larger than the sum of its proper divisors (37907211).

51691545 is a wasteful number, since it uses less digits than its factorization.

51691545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1148712 (or 1148709 counting only the distinct ones).

The product of its digits is 27000, while the sum is 36.

The square root of 51691545 is about 7189.6832336341. The cubic root of 51691545 is about 372.5116312450.

The spelling of 51691545 in words is "fifty-one million, six hundred ninety-one thousand, five hundred forty-five".