51239400 has 192 divisors, whose sum is σ = 171417600. Its totient is φ = 12629760.

The previous prime is 51239399. The next prime is 51239401. The reversal of 51239400 is 493215.

It is an interprime number because it is at equal distance from previous prime (51239399) and next prime (51239401).

It is a super-2 number, since 2×51239400² = 5250952224720000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (51239401) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 648561 + ... + 648639.

It is an arithmetic number, because the mean of its divisors is an integer number (892800).

Almost surely, 2^51239400 is an apocalyptic number.

51239400 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51239400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85708800).

51239400 is an abundant number, since it is smaller than the sum of its proper divisors (120178200).

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

51239400 is a wasteful number, since it uses less digits than its factorization.

51239400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168 (or 159 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 51239400 is about 7158.1701572399. The cubic root of 51239400 is about 371.4223315379.

The spelling of 51239400 in words is "fifty-one million, two hundred thirty-nine thousand, four hundred".