21013948 has 6 divisors (see below), whose sum is σ = 36774416. Its totient is φ = 10506972.

The previous prime is 21013933. The next prime is 21013961. The reversal of 21013948 is 84931012.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2626740 + ... + 2626747.

Almost surely, 2^21013948 is an apocalyptic number.

It is an amenable number.

21013948 is a deficient number, since it is larger than the sum of its proper divisors (15760468).

21013948 is a wasteful number, since it uses less digits than its factorization.

21013948 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5253491 (or 5253489 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 21013948 is about 4584.0972939064. The cubic root of 21013948 is about 275.9534858252.

The spelling of 21013948 in words is "twenty-one million, thirteen thousand, nine hundred forty-eight".