21532132397 has 8 divisors (see below), whose sum is σ = 22298048280. Its totient is φ = 20779536960.

The previous prime is 21532132393. The next prime is 21532132399. The reversal of 21532132397 is 79323123512.

It can be written as a sum of positive squares in 4 ways, for example, as 3961569481 + 17570562916 = 62941^2 + 132554^2 .

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 21532132397 - 2² = 21532132393 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21532132397.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21532132393) 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, 3326822 + ... + 3333287.

It is an arithmetic number, because the mean of its divisors is an integer number (2787256035).

Almost surely, 2^21532132397 is an apocalyptic number.

It is an amenable number.

21532132397 is a deficient number, since it is larger than the sum of its proper divisors (765915883).

21532132397 is an equidigital number, since it uses as much as digits as its factorization.

21532132397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6660223.

The product of its digits is 68040, while the sum is 38.

The spelling of 21532132397 in words is "twenty-one billion, five hundred thirty-two million, one hundred thirty-two thousand, three hundred ninety-seven".