20870408 has 32 divisors (see below), whose sum is σ = 42735000. Its totient is φ = 9497088.

The previous prime is 20870389. The next prime is 20870429. The reversal of 20870408 is 80407802.

It can be written as a sum of positive squares in 4 ways, for example, as 10745284 + 10125124 = 3278^2 + 3182^2 .

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, 6218 + ... + 8966.

Almost surely, 2^20870408 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20870408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21367500).

20870408 is an abundant number, since it is smaller than the sum of its proper divisors (21864592).

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

20870408 is a wasteful number, since it uses less digits than its factorization.

20870408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2841 (or 2837 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 29.

The square root of 20870408 is about 4568.4141668636. The cubic root of 20870408 is about 275.3237311495.

The spelling of 20870408 in words is "twenty million, eight hundred seventy thousand, four hundred eight".