220156421 has 4 divisors (see below), whose sum is σ = 222808992. Its totient is φ = 217503852.

The previous prime is 220156411. The next prime is 220156441. The reversal of 220156421 is 124651022.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 124651022 = 2 ⋅62325511.

It is a cyclic number.

It is not a de Polignac number, because 220156421 - 2⁶ = 220156357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220156411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1326161 + ... + 1326326.

It is an arithmetic number, because the mean of its divisors is an integer number (55702248).

Almost surely, 2^220156421 is an apocalyptic number.

It is an amenable number.

220156421 is a deficient number, since it is larger than the sum of its proper divisors (2652571).

220156421 is an equidigital number, since it uses as much as digits as its factorization.

220156421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2652570.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 220156421 is about 14837.6689880857. The cubic root of 220156421 is about 603.8241131137.

The spelling of 220156421 in words is "two hundred twenty million, one hundred fifty-six thousand, four hundred twenty-one".