21517725346 has 8 divisors (see below), whose sum is σ = 34759402524. Its totient is φ = 9931257840.

The previous prime is 21517725323. The next prime is 21517725347. The reversal of 21517725346 is 64352771512.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21469575625 + 48149721 = 146525^2 + 6939^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21517725347) 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, 413802385 + ... + 413802436.

Almost surely, 2^21517725346 is an apocalyptic number.

21517725346 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21517725346 is a deficient number, since it is larger than the sum of its proper divisors (13241677178).

21517725346 is a wasteful number, since it uses less digits than its factorization.

21517725346 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 827604836.

The product of its digits is 352800, while the sum is 43.

The spelling of 21517725346 in words is "twenty-one billion, five hundred seventeen million, seven hundred twenty-five thousand, three hundred forty-six".