221274972821 has 32 divisors (see below), whose sum is σ = 257519149056. Its totient is φ = 186225480000.

The previous prime is 221274972791. The next prime is 221274972869. The reversal of 221274972821 is 128279472122.

It is a de Polignac number, because none of the positive numbers 2^k-221274972821 is a prime.

It is a super-2 number, since 2×221274972821² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221274972521) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 68695991 + ... + 68699211.

It is an arithmetic number, because the mean of its divisors is an integer number (8047473408).

Almost surely, 2^221274972821 is an apocalyptic number.

It is an amenable number.

221274972821 is a deficient number, since it is larger than the sum of its proper divisors (36244176235).

221274972821 is a wasteful number, since it uses less digits than its factorization.

221274972821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4113.

The product of its digits is 451584, while the sum is 47.

The spelling of 221274972821 in words is "two hundred twenty-one billion, two hundred seventy-four million, nine hundred seventy-two thousand, eight hundred twenty-one".