21045948 has 48 divisors (see below), whose sum is σ = 61227264. Its totient is φ = 5466240.

The previous prime is 21045917. The next prime is 21045961. The reversal of 21045948 is 84954012.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10465 + ... + 12312.

It is an arithmetic number, because the mean of its divisors is an integer number (1275568).

Almost surely, 2^21045948 is an apocalyptic number.

21045948 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21045948 is an abundant number, since it is smaller than the sum of its proper divisors (40181316).

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

21045948 is a wasteful number, since it uses less digits than its factorization.

21045948 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22802 (or 22800 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 21045948 is about 4587.5862934663. The cubic root of 21045948 is about 276.0934885982.

The spelling of 21045948 in words is "twenty-one million, forty-five thousand, nine hundred forty-eight".