21213403645255 has 16 divisors (see below), whose sum is σ = 25545535372224. Its totient is φ = 16911100576000.

The previous prime is 21213403645249. The next prime is 21213403645261. The reversal of 21213403645255 is 55254630431212.

It is an interprime number because it is at equal distance from previous prime (21213403645249) and next prime (21213403645261).

It is not a de Polignac number, because 21213403645255 - 2⁹ = 21213403644743 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13936755 + ... + 15383755.

It is an arithmetic number, because the mean of its divisors is an integer number (1596595960764).

Almost surely, 2^{21213403645255} is an apocalyptic number.

21213403645255 is a deficient number, since it is larger than the sum of its proper divisors (4332131726969).

21213403645255 is a wasteful number, since it uses less digits than its factorization.

21213403645255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1457306.

The product of its (nonzero) digits is 864000, while the sum is 43.

The spelling of 21213403645255 in words is "twenty-one trillion, two hundred thirteen billion, four hundred three million, six hundred forty-five thousand, two hundred fifty-five".