21355420261265 has 8 divisors (see below), whose sum is σ = 26975267698560. Its totient is φ = 16185160618992.

The previous prime is 21355420261223. The next prime is 21355420261291. The reversal of 21355420261265 is 56216202455312.

It is a happy number.

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 21355420261265 - 2²⁶ = 21355353152401 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, 112396948649 + ... + 112396948838.

It is an arithmetic number, because the mean of its divisors is an integer number (3371908462320).

Almost surely, 2^{21355420261265} is an apocalyptic number.

It is an amenable number.

21355420261265 is a deficient number, since it is larger than the sum of its proper divisors (5619847437295).

21355420261265 is a wasteful number, since it uses less digits than its factorization.

21355420261265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224793897511.

The product of its (nonzero) digits is 864000, while the sum is 44.

The spelling of 21355420261265 in words is "twenty-one trillion, three hundred fifty-five billion, four hundred twenty million, two hundred sixty-one thousand, two hundred sixty-five".