20990030 has 32 divisors (see below), whose sum is σ = 39688704. Its totient is φ = 7977376.

The previous prime is 20990029. The next prime is 20990033. The reversal of 20990030 is 3009902.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a junction number, because it is equal to n+sod(n) for n = 20989978 and 20990005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20990033) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60317 + ... + 60663.

It is an arithmetic number, because the mean of its divisors is an integer number (1240272).

Almost surely, 2^20990030 is an apocalyptic number.

20990030 is a deficient number, since it is larger than the sum of its proper divisors (18698674).

20990030 is a wasteful number, since it uses less digits than its factorization.

20990030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 640.

The product of its (nonzero) digits is 486, while the sum is 23.

The square root of 20990030 is about 4581.4877496289. The cubic root of 20990030 is about 275.8487496568.

Adding to 20990030 its reverse (3009902), we get a palindrome (23999932).

The spelling of 20990030 in words is "twenty million, nine hundred ninety thousand, thirty".