21732156 has 36 divisors (see below), whose sum is σ = 55213704. Its totient is φ = 7207200.

The previous prime is 21732131. The next prime is 21732169. The reversal of 21732156 is 65123712.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6166 + ... + 9026.

It is an arithmetic number, because the mean of its divisors is an integer number (1533714).

Almost surely, 2^21732156 is an apocalyptic number.

It is an amenable number.

21732156 is an abundant number, since it is smaller than the sum of its proper divisors (33481548).

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

21732156 is a wasteful number, since it uses less digits than its factorization.

21732156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3082 (or 3077 counting only the distinct ones).

The product of its digits is 2520, while the sum is 27.

The square root of 21732156 is about 4661.7760563974. The cubic root of 21732156 is about 279.0621513367.

Adding to 21732156 its reverse (65123712), we get a palindrome (86855868).

The spelling of 21732156 in words is "twenty-one million, seven hundred thirty-two thousand, one hundred fifty-six".