51511761 has 16 divisors (see below), whose sum is σ = 87216000. Its totient is φ = 29435184.

The previous prime is 51511741. The next prime is 51511763. The reversal of 51511761 is 16711515.

It is a happy number.

It is not a de Polignac number, because 51511761 - 2⁹ = 51511249 is a prime.

It is a super-2 number, since 2×51511761² = 5306923042642242, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51511763) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 136086 + ... + 136463.

It is an arithmetic number, because the mean of its divisors is an integer number (5451000).

Almost surely, 2^51511761 is an apocalyptic number.

It is an amenable number.

51511761 is a deficient number, since it is larger than the sum of its proper divisors (35704239).

51511761 is a wasteful number, since it uses less digits than its factorization.

51511761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272565 (or 272559 counting only the distinct ones).

The product of its digits is 1050, while the sum is 27.

The square root of 51511761 is about 7177.1694281242. The cubic root of 51511761 is about 372.0792625067.

The spelling of 51511761 in words is "fifty-one million, five hundred eleven thousand, seven hundred sixty-one".