21534265563400 has 192 divisors, whose sum is σ = 52858671292800. Its totient is φ = 8142681845760.

The previous prime is 21534265563361. The next prime is 21534265563403. The reversal of 21534265563400 is 436556243512.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is not an unprimeable number, because it can be changed into a prime (21534265563403) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 180310906 + ... + 180430294.

It is an arithmetic number, because the mean of its divisors is an integer number (275305579650).

Almost surely, 2^{21534265563400} is an apocalyptic number.

21534265563400 is a gapful number since it is divisible by the number (20) 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 21534265563400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26429335646400).

21534265563400 is an abundant number, since it is smaller than the sum of its proper divisors (31324405729400).

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

21534265563400 is a wasteful number, since it uses less digits than its factorization.

21534265563400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119888 (or 119879 counting only the distinct ones).

The product of its (nonzero) digits is 2592000, while the sum is 46.

The spelling of 21534265563400 in words is "twenty-one trillion, five hundred thirty-four billion, two hundred sixty-five million, five hundred sixty-three thousand, four hundred".