21355435052544 has 40 divisors (see below), whose sum is σ = 56892213698760. Its totient is φ = 7118478350336.

The previous prime is 21355435052533. The next prime is 21355435052563. The reversal of 21355435052544 is 44525053455312.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a junction number, because it is equal to n+sod(n) for n = 21355435052493 and 21355435052502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6951637479 + ... + 6951640550.

It is an arithmetic number, because the mean of its divisors is an integer number (1422305342469).

Almost surely, 2^{21355435052544} is an apocalyptic number.

21355435052544 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21355435052544 is an abundant number, since it is smaller than the sum of its proper divisors (35536778646216).

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

21355435052544 is an equidigital number, since it uses as much as digits as its factorization.

21355435052544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13903278050 (or 13903278034 counting only the distinct ones).

The product of its (nonzero) digits is 7200000, while the sum is 48.

The spelling of 21355435052544 in words is "twenty-one trillion, three hundred fifty-five billion, four hundred thirty-five million, fifty-two thousand, five hundred forty-four".