21265017355 has 8 divisors (see below), whose sum is σ = 25518899952. Its totient is φ = 17011427808.

The previous prime is 21265017349. The next prime is 21265017391. The reversal of 21265017355 is 55371056212.

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 21265017355 - 2¹³ = 21265009163 is a prime.

It is a Duffinian number.

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, 146097 + ... + 252733.

It is an arithmetic number, because the mean of its divisors is an integer number (3189862494).

Almost surely, 2^21265017355 is an apocalyptic number.

21265017355 is a deficient number, since it is larger than the sum of its proper divisors (4253882597).

21265017355 is a wasteful number, since it uses less digits than its factorization.

21265017355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146525.

The product of its (nonzero) digits is 63000, while the sum is 37.

The spelling of 21265017355 in words is "twenty-one billion, two hundred sixty-five million, seventeen thousand, three hundred fifty-five".