51121231400 has 48 divisors (see below), whose sum is σ = 119167372800. Its totient is φ = 20395071680.

The previous prime is 51121231373. The next prime is 51121231409. The reversal of 51121231400 is 413212115.

It is a super-2 number, since 2×51121231400² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (51121231409) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 257090 + ... + 410289.

It is an arithmetic number, because the mean of its divisors is an integer number (2482653600).

Almost surely, 2^51121231400 is an apocalyptic number.

51121231400 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

51121231400 is an abundant number, since it is smaller than the sum of its proper divisors (68046141400).

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

51121231400 is a wasteful number, since it uses less digits than its factorization.

51121231400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 667778 (or 667769 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

Adding to 51121231400 its reverse (413212115), we get a palindrome (51534443515).

The spelling of 51121231400 in words is "fifty-one billion, one hundred twenty-one million, two hundred thirty-one thousand, four hundred".