20506615290 has 320 divisors, whose sum is σ = 64935763200. Its totient is φ = 4546160640.

The previous prime is 20506615253. The next prime is 20506615307. The reversal of 20506615290 is 9251660502.

20506615290 is a `hidden beast` number, since 2 + 0 + 506 + 61 + 5 + 2 + 90 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 58758036 + ... + 58758384.

It is an arithmetic number, because the mean of its divisors is an integer number (202924260).

Almost surely, 2^20506615290 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20506615290, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32467881600).

20506615290 is an abundant number, since it is smaller than the sum of its proper divisors (44429147910).

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

20506615290 is a wasteful number, since it uses less digits than its factorization.

20506615290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 659 (or 650 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The spelling of 20506615290 in words is "twenty billion, five hundred six million, six hundred fifteen thousand, two hundred ninety".