21697962 has 80 divisors (see below), whose sum is σ = 54112800. Its totient is φ = 5749920.

The previous prime is 21697961. The next prime is 21697969. The reversal of 21697962 is 26979612.

Its product of digits (81648) is a multiple of the sum of its prime divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21697961) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1141989 + ... + 1142007.

It is an arithmetic number, because the mean of its divisors is an integer number (676410).

Almost surely, 2^21697962 is an apocalyptic number.

21697962 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21697962, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27056400).

21697962 is an abundant number, since it is smaller than the sum of its proper divisors (32414838).

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

21697962 is a wasteful number, since it uses less digits than its factorization.

21697962 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81 (or 48 counting only the distinct ones).

The product of its digits is 81648, while the sum is 42.

The square root of 21697962 is about 4658.1071262907. The cubic root of 21697962 is about 278.9157130317.

The spelling of 21697962 in words is "twenty-one million, six hundred ninety-seven thousand, nine hundred sixty-two".