20749128 has 32 divisors (see below), whose sum is σ = 54129600. Its totient is φ = 6615488.

The previous prime is 20749117. The next prime is 20749139. The reversal of 20749128 is 82194702.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20749117) and next prime (20749139).

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, 18243 + ... + 19346.

It is an arithmetic number, because the mean of its divisors is an integer number (1691550).

Almost surely, 2^20749128 is an apocalyptic number.

It is an amenable number.

20749128 is an abundant number, since it is smaller than the sum of its proper divisors (33380472).

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

20749128 is a wasteful number, since it uses less digits than its factorization.

20749128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37621 (or 37617 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 20749128 is about 4555.1210741318. The cubic root of 20749128 is about 274.7893836384.

The spelling of 20749128 in words is "twenty million, seven hundred forty-nine thousand, one hundred twenty-eight".