20628990 has 96 divisors (see below), whose sum is σ = 57788640. Its totient is φ = 5087232.

The previous prime is 20628983. The next prime is 20629019. The reversal of 20628990 is 9982602.

20628990 is a `hidden beast` number, since 20 + 628 + 9 + 9 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 148341 + ... + 148479.

It is an arithmetic number, because the mean of its divisors is an integer number (601965).

Almost surely, 2^20628990 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20628990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28894320).

20628990 is an abundant number, since it is smaller than the sum of its proper divisors (37159650).

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

20628990 is a wasteful number, since it uses less digits than its factorization.

20628990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 266 (or 263 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 20628990 is about 4541.9147944452. The cubic root of 20628990 is about 274.2580108274.

The spelling of 20628990 in words is "twenty million, six hundred twenty-eight thousand, nine hundred ninety".