21537948 has 12 divisors (see below), whose sum is σ = 50255240. Its totient is φ = 7179312.

The previous prime is 21537937. The next prime is 21537961. The reversal of 21537948 is 84973512.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 897403 + ... + 897426.

Almost surely, 2^21537948 is an apocalyptic number.

It is an amenable number.

21537948 is an abundant number, since it is smaller than the sum of its proper divisors (28717292).

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

21537948 is a wasteful number, since it uses less digits than its factorization.

21537948 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1794836 (or 1794834 counting only the distinct ones).

The product of its digits is 60480, while the sum is 39.

The square root of 21537948 is about 4640.8994817815. The cubic root of 21537948 is about 278.2283891677.

It can be divided in two parts, 2153 and 7948, that added together give a palindrome (10101).

The spelling of 21537948 in words is "twenty-one million, five hundred thirty-seven thousand, nine hundred forty-eight".