21406489597 has 4 divisors (see below), whose sum is σ = 22337206560. Its totient is φ = 20475772636.

The previous prime is 21406489583. The next prime is 21406489609. The reversal of 21406489597 is 79598460412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21406489597 - 2⁷ = 21406489469 is a prime.

It is a super-3 number, since 3×21406489597³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21406489547) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 465358447 + ... + 465358492.

It is an arithmetic number, because the mean of its divisors is an integer number (5584301640).

Almost surely, 2^21406489597 is an apocalyptic number.

It is an amenable number.

21406489597 is a deficient number, since it is larger than the sum of its proper divisors (930716963).

21406489597 is an equidigital number, since it uses as much as digits as its factorization.

21406489597 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 930716962.

The product of its (nonzero) digits is 4354560, while the sum is 55.

The spelling of 21406489597 in words is "twenty-one billion, four hundred six million, four hundred eighty-nine thousand, five hundred ninety-seven".