20699820 has 48 divisors (see below), whose sum is σ = 64401120. Its totient is φ = 5519808.

The previous prime is 20699803. The next prime is 20699827. The reversal of 20699820 is 2899602.

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

It is not an unprimeable number, because it can be changed into a prime (20699827) 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, 18627 + ... + 19706.

It is an arithmetic number, because the mean of its divisors is an integer number (1341690).

Almost surely, 2^20699820 is an apocalyptic number.

20699820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20699820 is an abundant number, since it is smaller than the sum of its proper divisors (43701300).

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

20699820 is a wasteful number, since it uses less digits than its factorization.

20699820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38351 (or 38343 counting only the distinct ones).

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

The square root of 20699820 is about 4549.7054849737. The cubic root of 20699820 is about 274.5715421636.

The spelling of 20699820 in words is "twenty million, six hundred ninety-nine thousand, eight hundred twenty".