21722502 has 16 divisors (see below), whose sum is σ = 44182080. Its totient is φ = 7117992.

The previous prime is 21722489. The next prime is 21722509. The reversal of 21722502 is 20522712.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21722509) 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 7 ways as a sum of consecutive naturals, for example, 30328 + ... + 31035.

It is an arithmetic number, because the mean of its divisors is an integer number (2761380).

Almost surely, 2^21722502 is an apocalyptic number.

21722502 is an abundant number, since it is smaller than the sum of its proper divisors (22459578).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21722502 is a wasteful number, since it uses less digits than its factorization.

21722502 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61427.

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 21722502 is about 4660.7404991053. The cubic root of 21722502 is about 279.0208229471.

The spelling of 21722502 in words is "twenty-one million, seven hundred twenty-two thousand, five hundred two".