21001292 has 36 divisors (see below), whose sum is σ = 40705056. Its totient is φ = 9472320.

The previous prime is 21001247. The next prime is 21001319. The reversal of 21001292 is 29210012.

It is a self number, because there is not a number n which added to its sum of digits gives 21001292.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 31442 + ... + 32102.

It is an arithmetic number, because the mean of its divisors is an integer number (1130696).

Almost surely, 2^21001292 is an apocalyptic number.

It is an amenable number.

21001292 is a deficient number, since it is larger than the sum of its proper divisors (19703764).

21001292 is a wasteful number, since it uses less digits than its factorization.

21001292 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 738 (or 723 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 21001292 is about 4582.7166615448. The cubic root of 21001292 is about 275.8980755063.

The spelling of 21001292 in words is "twenty-one million, one thousand, two hundred ninety-two".