21457765425 has 48 divisors (see below), whose sum is σ = 37616967360. Its totient is φ = 10762583040.

The previous prime is 21457765421. The next prime is 21457765531. The reversal of 21457765425 is 52456775412.

It is not a de Polignac number, because 21457765425 - 2² = 21457765421 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21457765421) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 140269 + ... + 250181.

It is an arithmetic number, because the mean of its divisors is an integer number (783686820).

Almost surely, 2^21457765425 is an apocalyptic number.

21457765425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21457765425 is a deficient number, since it is larger than the sum of its proper divisors (16159201935).

21457765425 is a wasteful number, since it uses less digits than its factorization.

21457765425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110082 (or 110077 counting only the distinct ones).

The product of its digits is 2352000, while the sum is 48.

The spelling of 21457765425 in words is "twenty-one billion, four hundred fifty-seven million, seven hundred sixty-five thousand, four hundred twenty-five".