221646331651331 has 4 divisors (see below), whose sum is σ = 222794758240392. Its totient is φ = 220497905062272.

The previous prime is 221646331651309. The next prime is 221646331651333. The reversal of 221646331651331 is 133156133646122.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 221646331651331 - 2¹⁰ = 221646331650307 is a prime.

It is a super-2 number, since 2×221646331651331² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221646331651333) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 574213294241 + ... + 574213294626.

It is an arithmetic number, because the mean of its divisors is an integer number (55698689560098).

Almost surely, 2^{221646331651331} is an apocalyptic number.

221646331651331 is a deficient number, since it is larger than the sum of its proper divisors (1148426589061).

221646331651331 is a wasteful number, since it uses less digits than its factorization.

221646331651331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1148426589060.

The product of its digits is 1399680, while the sum is 47.

The spelling of 221646331651331 in words is "two hundred twenty-one trillion, six hundred forty-six billion, three hundred thirty-one million, six hundred fifty-one thousand, three hundred thirty-one".