21064026340 has 48 divisors (see below), whose sum is σ = 51786693504. Its totient is φ = 7045804800.

The previous prime is 21064026337. The next prime is 21064026349. The reversal of 21064026340 is 4362046012.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 21064026299 and 21064026308.

It is not an unprimeable number, because it can be changed into a prime (21064026349) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1829106 + ... + 1840585.

It is an arithmetic number, because the mean of its divisors is an integer number (1078889448).

Almost surely, 2^21064026340 is an apocalyptic number.

21064026340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21064026340 is an abundant number, since it is smaller than the sum of its proper divisors (30722667164).

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

21064026340 is a wasteful number, since it uses less digits than its factorization.

21064026340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3669748 (or 3669746 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 28.

The spelling of 21064026340 in words is "twenty-one billion, sixty-four million, twenty-six thousand, three hundred forty".