21111497904 has 120 divisors (see below), whose sum is σ = 63484889088. Its totient is φ = 6027799680.

The previous prime is 21111497893. The next prime is 21111497917. The reversal of 21111497904 is 40979411112.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6224049 + ... + 6227439.

Almost surely, 2^21111497904 is an apocalyptic number.

21111497904 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21111497904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31742444544).

21111497904 is an abundant number, since it is smaller than the sum of its proper divisors (42373391184).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21111497904 is a wasteful number, since it uses less digits than its factorization.

21111497904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6063 (or 6050 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 39.

The spelling of 21111497904 in words is "twenty-one billion, one hundred eleven million, four hundred ninety-seven thousand, nine hundred four".