51291900 has 216 divisors, whose sum is σ = 182401520. Its totient is φ = 12355200.

The previous prime is 51291883. The next prime is 51291967. The reversal of 51291900 is 919215.

It is a happy number.

It is a super-2 number, since 2×51291900² = 5261718011220000, 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 an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 326622 + ... + 326778.

Almost surely, 2^51291900 is an apocalyptic number.

51291900 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 51291900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91200760).

51291900 is an abundant number, since it is smaller than the sum of its proper divisors (131109620).

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

51291900 is a wasteful number, since it uses less digits than its factorization.

51291900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202 (or 178 counting only the distinct ones).

The product of its (nonzero) digits is 810, while the sum is 27.

The square root of 51291900 is about 7161.8363566895. The cubic root of 51291900 is about 371.5491416124.

The spelling of 51291900 in words is "fifty-one million, two hundred ninety-one thousand, nine hundred".