221145111631 has 4 divisors (see below), whose sum is σ = 221465148664. Its totient is φ = 220825074600.

The previous prime is 221145111617. The next prime is 221145111637. The reversal of 221145111631 is 136111541122.

It is a happy number.

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 221145111631 - 2⁷ = 221145111503 is a prime.

It is a super-2 number, since 2×221145111631² (a number of 23 digits) contains 22 as substring.

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 221145111631.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221145111637) 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, 160017480 + ... + 160018861.

It is an arithmetic number, because the mean of its divisors is an integer number (55366287166).

Almost surely, 2^221145111631 is an apocalyptic number.

221145111631 is a deficient number, since it is larger than the sum of its proper divisors (320037033).

221145111631 is an equidigital number, since it uses as much as digits as its factorization.

221145111631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320037032.

The product of its digits is 1440, while the sum is 28.

Adding to 221145111631 its reverse (136111541122), we get a palindrome (357256652753).

The spelling of 221145111631 in words is "two hundred twenty-one billion, one hundred forty-five million, one hundred eleven thousand, six hundred thirty-one".