222720921 has 24 divisors (see below), whose sum is σ = 340738944. Its totient is φ = 145314000.

The previous prime is 222720919. The next prime is 222720959. The reversal of 222720921 is 129027222.

It is not a de Polignac number, because 222720921 - 2¹ = 222720919 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (222720991) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1671 + ... + 21171.

It is an arithmetic number, because the mean of its divisors is an integer number (14197456).

Almost surely, 2^222720921 is an apocalyptic number.

It is an amenable number.

222720921 is a deficient number, since it is larger than the sum of its proper divisors (118018023).

222720921 is an equidigital number, since it uses as much as digits as its factorization.

222720921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19563 (or 19551 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 222720921 is about 14923.8373416491. The cubic root of 222720921 is about 606.1596236696.

The spelling of 222720921 in words is "two hundred twenty-two million, seven hundred twenty thousand, nine hundred twenty-one".