21325997 has 8 divisors (see below), whose sum is σ = 26588352. Its totient is φ = 16617600.

The previous prime is 21325957. The next prime is 21326017. The reversal of 21325997 is 79952312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21325997 - 2²² = 17131693 is a prime.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 21325997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21325957) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 138404 + ... + 138557.

It is an arithmetic number, because the mean of its divisors is an integer number (3323544).

Almost surely, 2^21325997 is an apocalyptic number.

It is an amenable number.

21325997 is a deficient number, since it is larger than the sum of its proper divisors (5262355).

21325997 is a wasteful number, since it uses less digits than its factorization.

21325997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276979.

The product of its digits is 34020, while the sum is 38.

The square root of 21325997 is about 4618.0079038477. The cubic root of 21325997 is about 277.3127140363.

It can be divided in two parts, 21325 and 997, that added together give a palindrome (22322).

The spelling of 21325997 in words is "twenty-one million, three hundred twenty-five thousand, nine hundred ninety-seven".