21170020185451 has 8 divisors (see below), whose sum is σ = 22093516062720. Its totient is φ = 20246779326312.

The previous prime is 21170020185427. The next prime is 21170020185467. The reversal of 21170020185451 is 15458102007112.

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 21170020185451 - 2³³ = 21161430250859 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21170020185451.

It is not an unprimeable number, because it can be changed into a prime (21170020185401) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 63584875 + ... + 63916948.

It is an arithmetic number, because the mean of its divisors is an integer number (2761689507840).

Almost surely, 2^{21170020185451} is an apocalyptic number.

21170020185451 is a deficient number, since it is larger than the sum of its proper divisors (923495877269).

21170020185451 is a wasteful number, since it uses less digits than its factorization.

21170020185451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127509065.

The product of its (nonzero) digits is 22400, while the sum is 37.

The spelling of 21170020185451 in words is "twenty-one trillion, one hundred seventy billion, twenty million, one hundred eighty-five thousand, four hundred fifty-one".