21351020235555 has 8 divisors (see below), whose sum is σ = 34161632376912. Its totient is φ = 11387210792288.

The previous prime is 21351020235511. The next prime is 21351020235599. The reversal of 21351020235555 is 55553202015312.

It is an interprime number because it is at equal distance from previous prime (21351020235511) and next prime (21351020235599).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21351020235555 - 2²⁴ = 21351003458339 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 711700674504 + ... + 711700674533.

It is an arithmetic number, because the mean of its divisors is an integer number (4270204047114).

Almost surely, 2^{21351020235555} is an apocalyptic number.

21351020235555 is a deficient number, since it is larger than the sum of its proper divisors (12810612141357).

21351020235555 is a wasteful number, since it uses less digits than its factorization.

21351020235555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1423401349045.

The product of its (nonzero) digits is 225000, while the sum is 39.

The spelling of 21351020235555 in words is "twenty-one trillion, three hundred fifty-one billion, twenty million, two hundred thirty-five thousand, five hundred fifty-five".