21090409734675 has 24 divisors (see below), whose sum is σ = 34869927199680. Its totient is φ = 11248073437600.

The previous prime is 21090409734673. The next prime is 21090409734679. The reversal of 21090409734675 is 57643790409012.

It is a happy number.

It is not a de Polignac number, because 21090409734675 - 2¹ = 21090409734673 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21090409734673) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4170460 + ... + 7718390.

It is an arithmetic number, because the mean of its divisors is an integer number (1452913633320).

Almost surely, 2^{21090409734675} is an apocalyptic number.

21090409734675 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21090409734675 is a deficient number, since it is larger than the sum of its proper divisors (13779517465005).

21090409734675 is a wasteful number, since it uses less digits than its factorization.

21090409734675 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3627203 (or 3627198 counting only the distinct ones).

The product of its (nonzero) digits is 11430720, while the sum is 57.

The spelling of 21090409734675 in words is "twenty-one trillion, ninety billion, four hundred nine million, seven hundred thirty-four thousand, six hundred seventy-five".