21049902 has 32 divisors (see below), whose sum is σ = 47577600. Its totient is φ = 6896664.

The previous prime is 21049883. The next prime is 21049907. The reversal of 21049902 is 20994012.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21049907) 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, 118 + ... + 6489.

It is an arithmetic number, because the mean of its divisors is an integer number (1486800).

Almost surely, 2^21049902 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21049902, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23788800).

21049902 is an abundant number, since it is smaller than the sum of its proper divisors (26527698).

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

21049902 is a wasteful number, since it uses less digits than its factorization.

21049902 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6677 (or 6671 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 21049902 is about 4588.0172187994. The cubic root of 21049902 is about 276.1107778375.

The spelling of 21049902 in words is "twenty-one million, forty-nine thousand, nine hundred two".