51131340 has 72 divisors (see below), whose sum is σ = 167036688. Its totient is φ = 12585600.

The previous prime is 51131303. The next prime is 51131383. The reversal of 51131340 is 4313115.

It is a super-2 number, since 2×51131340² = 5228827860391200, which contains 22 as substring.

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

It is a zygodrome in base 2.

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, 8586 + ... + 13265.

It is an arithmetic number, because the mean of its divisors is an integer number (2319954).

Almost surely, 2^51131340 is an apocalyptic number.

It is an amenable number.

51131340 is an abundant number, since it is smaller than the sum of its proper divisors (115905348).

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

51131340 is a wasteful number, since it uses less digits than its factorization.

51131340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21879 (or 21874 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 51131340 is about 7150.6181550968. The cubic root of 51131340 is about 371.1610472868.

Adding to 51131340 its reverse (4313115), we get a palindrome (55444455).

The spelling of 51131340 in words is "fifty-one million, one hundred thirty-one thousand, three hundred forty".