21425321615 has 16 divisors (see below), whose sum is σ = 26049171456. Its totient is φ = 16914861600.

The previous prime is 21425321591. The next prime is 21425321647. The reversal of 21425321615 is 51612352412.

It is not a de Polignac number, because 21425321615 - 2²² = 21421127311 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 349730 + ... + 406400.

It is an arithmetic number, because the mean of its divisors is an integer number (1628073216).

Almost surely, 2^21425321615 is an apocalyptic number.

21425321615 is a deficient number, since it is larger than the sum of its proper divisors (4623849841).

21425321615 is an equidigital number, since it uses as much as digits as its factorization.

21425321615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57670.

The product of its digits is 14400, while the sum is 32.

The spelling of 21425321615 in words is "twenty-one billion, four hundred twenty-five million, three hundred twenty-one thousand, six hundred fifteen".