15500021400 has 144 divisors (see below), whose sum is σ = 54794056200. Its totient is φ = 3915786240.

The previous prime is 15500021363. The next prime is 15500021429. The reversal of 15500021400 is 412000551.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 192409 + ... + 260808.

Almost surely, 2^15500021400 is an apocalyptic number.

15500021400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15500021400 is an abundant number, since it is smaller than the sum of its proper divisors (39294034800).

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

15500021400 is a wasteful number, since it uses less digits than its factorization.

15500021400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 453258 (or 453246 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

Adding to 15500021400 its reverse (412000551), we get a palindrome (15912021951).

It can be divided in two parts, 155000 and 21400, that added together give a square (176400 = 420²).

The spelling of 15500021400 in words is "fifteen billion, five hundred million, twenty-one thousand, four hundred".