20999340 has 36 divisors (see below), whose sum is σ = 63698544. Its totient is φ = 5599776.

The previous prime is 20999317. The next prime is 20999357. The reversal of 20999340 is 4399902.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20999295 and 20999304.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 58152 + ... + 58511.

It is an arithmetic number, because the mean of its divisors is an integer number (1769404).

Almost surely, 2^20999340 is an apocalyptic number.

20999340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20999340 is an abundant number, since it is smaller than the sum of its proper divisors (42699204).

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

20999340 is a wasteful number, since it uses less digits than its factorization.

20999340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116678 (or 116673 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 36.

The square root of 20999340 is about 4582.5036824862. The cubic root of 20999340 is about 275.8895273063.

The spelling of 20999340 in words is "twenty million, nine hundred ninety-nine thousand, three hundred forty".