21049388 has 12 divisors (see below), whose sum is σ = 37216872. Its totient is φ = 10416000.

The previous prime is 21049387. The next prime is 21049493. The reversal of 21049388 is 88394012.

It is a happy number.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21049387) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26738 + ... + 27513.

It is an arithmetic number, because the mean of its divisors is an integer number (3101406).

Almost surely, 2^21049388 is an apocalyptic number.

It is an amenable number.

21049388 is a deficient number, since it is larger than the sum of its proper divisors (16167484).

21049388 is a wasteful number, since it uses less digits than its factorization.

21049388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54352 (or 54350 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 21049388 is about 4587.9612029746. The cubic root of 21049388 is about 276.1085304463.

The spelling of 21049388 in words is "twenty-one million, forty-nine thousand, three hundred eighty-eight".