21153513400 has 48 divisors (see below), whose sum is σ = 50768447040. Its totient is φ = 8188454400.

The previous prime is 21153513397. The next prime is 21153513401. The reversal of 21153513400 is 431535112.

It is a happy number.

It is a super-2 number, since 2×21153513400² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21153513401) 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, 1699729 + ... + 1712128.

It is an arithmetic number, because the mean of its divisors is an integer number (1057675980).

Almost surely, 2^21153513400 is an apocalyptic number.

21153513400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21153513400 is an abundant number, since it is smaller than the sum of its proper divisors (29614933640).

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

21153513400 is a wasteful number, since it uses less digits than its factorization.

21153513400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3411904 (or 3411895 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 25.

The spelling of 21153513400 in words is "twenty-one billion, one hundred fifty-three million, five hundred thirteen thousand, four hundred".