21259117040 has 40 divisors (see below), whose sum is σ = 56488512480. Its totient is φ = 7288839936.

The previous prime is 21259117021. The next prime is 21259117057. The reversal of 21259117040 is 4071195212.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 21259116988 and 21259117006.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18980795 + ... + 18981914.

It is an arithmetic number, because the mean of its divisors is an integer number (1412212812).

Almost surely, 2^21259117040 is an apocalyptic number.

21259117040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21259117040 is an abundant number, since it is smaller than the sum of its proper divisors (35229395440).

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

21259117040 is a wasteful number, since it uses less digits than its factorization.

21259117040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37962729 (or 37962723 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 32.

The spelling of 21259117040 in words is "twenty-one billion, two hundred fifty-nine million, one hundred seventeen thousand, forty".