21728674 has 32 divisors (see below), whose sum is σ = 36900864. Its totient is φ = 9510480.

The previous prime is 21728671. The next prime is 21728677. The reversal of 21728674 is 47682712.

It is an interprime number because it is at equal distance from previous prime (21728671) and next prime (21728677).

It is not an unprimeable number, because it can be changed into a prime (21728671) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 97327 + ... + 97549.

It is an arithmetic number, because the mean of its divisors is an integer number (1153152).

Almost surely, 2^21728674 is an apocalyptic number.

21728674 is a deficient number, since it is larger than the sum of its proper divisors (15172190).

21728674 is a wasteful number, since it uses less digits than its factorization.

21728674 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 382.

The product of its digits is 37632, while the sum is 37.

The square root of 21728674 is about 4661.4025786237. The cubic root of 21728674 is about 279.0472464448.

The spelling of 21728674 in words is "twenty-one million, seven hundred twenty-eight thousand, six hundred seventy-four".