21023532 has 36 divisors (see below), whose sum is σ = 53312896. Its totient is φ = 6985440.

The previous prime is 21023531. The next prime is 21023533. The reversal of 21023532 is 23532012.

It is an interprime number because it is at equal distance from previous prime (21023531) and next prime (21023533).

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21023531) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13557 + ... + 15027.

Almost surely, 2^21023532 is an apocalyptic number.

It is an amenable number.

21023532 is an abundant number, since it is smaller than the sum of its proper divisors (32289364).

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

21023532 is a wasteful number, since it uses less digits than its factorization.

21023532 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1878 (or 1873 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 18.

The square root of 21023532 is about 4585.1425277738. The cubic root of 21023532 is about 275.9954315564.

Adding to 21023532 its reverse (23532012), we get a palindrome (44555544).

The spelling of 21023532 in words is "twenty-one million, twenty-three thousand, five hundred thirty-two".