20405704 has 32 divisors (see below), whose sum is σ = 41912640. Its totient is φ = 9236800.

The previous prime is 20405683. The next prime is 20405713. The reversal of 20405704 is 40750402.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40317 + ... + 40819.

It is an arithmetic number, because the mean of its divisors is an integer number (1309770).

Almost surely, 2^20405704 is an apocalyptic number.

It is an amenable number.

20405704 is an abundant number, since it is smaller than the sum of its proper divisors (21506936).

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

20405704 is a wasteful number, since it uses less digits than its factorization.

20405704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 981 (or 977 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 22.

The square root of 20405704 is about 4517.2673155349. The cubic root of 20405704 is about 273.2649058666.

It can be divided in two parts, 2040 and 5704, that added together give a square (7744 = 88²).

The spelling of 20405704 in words is "twenty million, four hundred five thousand, seven hundred four".