21000403553610 has 128 divisors (see below), whose sum is σ = 57274260503040. Its totient is φ = 4889019396096.

The previous prime is 21000403553609. The next prime is 21000403553629. The reversal of 21000403553610 is 1635530400012.

It is a super-2 number, since 2×21000403553610² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 12354379 + ... + 13951038.

It is an arithmetic number, because the mean of its divisors is an integer number (447455160180).

Almost surely, 2^{21000403553610} is an apocalyptic number.

21000403553610 is an abundant number, since it is smaller than the sum of its proper divisors (36273856949430).

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

21000403553610 is a wasteful number, since it uses less digits than its factorization.

21000403553610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26305552.

The product of its (nonzero) digits is 10800, while the sum is 30.

Adding to 21000403553610 its reverse (1635530400012), we get a palindrome (22635933953622).

The spelling of 21000403553610 in words is "twenty-one trillion, four hundred three million, five hundred fifty-three thousand, six hundred ten".