51211530 has 48 divisors (see below), whose sum is σ = 133739424. Its totient is φ = 13596000.

The previous prime is 51211507. The next prime is 51211541. The reversal of 51211530 is 3511215.

51211530 is a `hidden beast` number, since 512 + 1 + 153 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21457 + ... + 23723.

It is an arithmetic number, because the mean of its divisors is an integer number (2786238).

Almost surely, 2^51211530 is an apocalyptic number.

51211530 is an abundant number, since it is smaller than the sum of its proper divisors (82527894).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51211530 is a wasteful number, since it uses less digits than its factorization.

51211530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2531 (or 2528 counting only the distinct ones).

The product of its (nonzero) digits is 150, while the sum is 18.

The square root of 51211530 is about 7156.2231658886. The cubic root of 51211530 is about 371.3549783049.

Adding to 51211530 its reverse (3511215), we get a palindrome (54722745).

The spelling of 51211530 in words is "fifty-one million, two hundred eleven thousand, five hundred thirty".