20604990 has 96 divisors (see below), whose sum is σ = 58506624. Its totient is φ = 4630080.

The previous prime is 20604973. The next prime is 20605019. The reversal of 20604990 is 9940602.

20604990 is a nontrivial binomial coefficient, being equal to C(6420, 2).

It is a super-2 number, since 2×20604990² = 849131225800200, which contains 22 as substring.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 157225 + ... + 157355.

It is an arithmetic number, because the mean of its divisors is an integer number (609444).

Almost surely, 2^20604990 is an apocalyptic number.

20604990 is the 6419-th triangular number and also the 3210-th hexagonal number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20604990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29253312).

20604990 is an abundant number, since it is smaller than the sum of its proper divisors (37901634).

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

20604990 is a wasteful number, since it uses less digits than its factorization.

20604990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 262 (or 255 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 20604990 is about 4539.2719680583. The cubic root of 20604990 is about 274.1516112652.

The spelling of 20604990 in words is "twenty million, six hundred four thousand, nine hundred ninety".