21415842725 has 6 divisors (see below), whose sum is σ = 26555645010. Its totient is φ = 17132674160.

The previous prime is 21415842697. The next prime is 21415842779. The reversal of 21415842725 is 52724851412.

It can be written as a sum of positive squares in 3 ways, for example, as 1330717441 + 20085125284 = 36479^2 + 141722^2 .

It is not a de Polignac number, because 21415842725 - 2¹⁰ = 21415841701 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 428316830 + ... + 428316879.

It is an arithmetic number, because the mean of its divisors is an integer number (4425940835).

Almost surely, 2^21415842725 is an apocalyptic number.

21415842725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21415842725 is a deficient number, since it is larger than the sum of its proper divisors (5139802285).

21415842725 is an equidigital number, since it uses as much as digits as its factorization.

21415842725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 856633719 (or 856633714 counting only the distinct ones).

The product of its digits is 179200, while the sum is 41.

The spelling of 21415842725 in words is "twenty-one billion, four hundred fifteen million, eight hundred forty-two thousand, seven hundred twenty-five".