20813628408 has 32 divisors (see below), whose sum is σ = 53712591360. Its totient is φ = 6714073440.

The previous prime is 20813628397. The next prime is 20813628419. The reversal of 20813628408 is 80482631802.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20813628397) and next prime (20813628419).

It is a super-2 number, since 2×20813628408² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20813628408.

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, 13986910 + ... + 13988397.

It is an arithmetic number, because the mean of its divisors is an integer number (1678518480).

Almost surely, 2^20813628408 is an apocalyptic number.

It is an amenable number.

20813628408 is an abundant number, since it is smaller than the sum of its proper divisors (32898962952).

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

20813628408 is a wasteful number, since it uses less digits than its factorization.

20813628408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27975347 (or 27975343 counting only the distinct ones).

The product of its (nonzero) digits is 147456, while the sum is 42.

The spelling of 20813628408 in words is "twenty billion, eight hundred thirteen million, six hundred twenty-eight thousand, four hundred eight".