222151521 has 4 divisors (see below), whose sum is σ = 296202032. Its totient is φ = 148101012.

The previous prime is 222151511. The next prime is 222151541. The reversal of 222151521 is 125151222.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 222151521 - 2¹⁸ = 221889377 is a prime.

It is a super-2 number, since 2×222151521² = 98702596565226882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (222151511) 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, 37025251 + ... + 37025256.

It is an arithmetic number, because the mean of its divisors is an integer number (74050508).

Almost surely, 2^222151521 is an apocalyptic number.

It is an amenable number.

222151521 is a deficient number, since it is larger than the sum of its proper divisors (74050511).

222151521 is an equidigital number, since it uses as much as digits as its factorization.

222151521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74050510.

The product of its digits is 400, while the sum is 21.

The square root of 222151521 is about 14904.7482702661. The cubic root of 222151521 is about 605.6426211404.

The spelling of 222151521 in words is "two hundred twenty-two million, one hundred fifty-one thousand, five hundred twenty-one".