21598722 has 12 divisors (see below), whose sum is σ = 46797270. Its totient is φ = 7199568.

The previous prime is 21598673. The next prime is 21598727. The reversal of 21598722 is 22789512.

It can be written as a sum of positive squares in only one way, i.e., 14676561 + 6922161 = 3831^2 + 2631^2 .

It is not an unprimeable number, because it can be changed into a prime (21598727) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 599947 + ... + 599982.

Almost surely, 2^21598722 is an apocalyptic number.

21598722 is an abundant number, since it is smaller than the sum of its proper divisors (25198548).

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

21598722 is a wasteful number, since it uses less digits than its factorization.

21598722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1199937 (or 1199934 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The square root of 21598722 is about 4647.4425225063. The cubic root of 21598722 is about 278.4898373617.

The spelling of 21598722 in words is "twenty-one million, five hundred ninety-eight thousand, seven hundred twenty-two".