21729022 has 16 divisors (see below), whose sum is σ = 37524960. Its totient is φ = 9243648.

The previous prime is 21729017. The next prime is 21729031. The reversal of 21729022 is 22092712.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3747 + ... + 7582.

It is an arithmetic number, because the mean of its divisors is an integer number (2345310).

Almost surely, 2^21729022 is an apocalyptic number.

21729022 is a deficient number, since it is larger than the sum of its proper divisors (15795938).

21729022 is a wasteful number, since it uses less digits than its factorization.

21729022 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11475.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 21729022 is about 4661.4399062950. The cubic root of 21729022 is about 279.0487361495.

The spelling of 21729022 in words is "twenty-one million, seven hundred twenty-nine thousand, twenty-two".