51031215400 has 144 divisors (see below), whose sum is σ = 137497047840. Its totient is φ = 17465011200.

The previous prime is 51031215371. The next prime is 51031215437. The reversal of 51031215400 is 451213015.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 595669 + ... + 675931.

It is an arithmetic number, because the mean of its divisors is an integer number (954840610).

Almost surely, 2^51031215400 is an apocalyptic number.

51031215400 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 51031215400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68748523920).

51031215400 is an abundant number, since it is smaller than the sum of its proper divisors (86465832440).

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

51031215400 is a wasteful number, since it uses less digits than its factorization.

51031215400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80324 (or 80298 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 22.

Adding to 51031215400 its reverse (451213015), we get a palindrome (51482428415).

The spelling of 51031215400 in words is "fifty-one billion, thirty-one million, two hundred fifteen thousand, four hundred".