20999394 has 48 divisors (see below), whose sum is σ = 50162112. Its totient is φ = 6308064.

The previous prime is 20999383. The next prime is 20999401. The reversal of 20999394 is 49399902.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9019 + ... + 11105.

It is an arithmetic number, because the mean of its divisors is an integer number (1045044).

Almost surely, 2^20999394 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20999394, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25081056).

20999394 is an abundant number, since it is smaller than the sum of its proper divisors (29162718).

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

20999394 is a wasteful number, since it uses less digits than its factorization.

20999394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2151 (or 2148 counting only the distinct ones).

The product of its (nonzero) digits is 157464, while the sum is 45.

The square root of 20999394 is about 4582.5095744581. The cubic root of 20999394 is about 275.8897637903.

The spelling of 20999394 in words is "twenty million, nine hundred ninety-nine thousand, three hundred ninety-four".