20305724 has 6 divisors (see below), whose sum is σ = 35535024. Its totient is φ = 10152860.

The previous prime is 20305693. The next prime is 20305777. The reversal of 20305724 is 42750302.

It is a self number, because there is not a number n which added to its sum of digits gives 20305724.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2538212 + ... + 2538219.

It is an arithmetic number, because the mean of its divisors is an integer number (5922504).

Almost surely, 2^20305724 is an apocalyptic number.

It is an amenable number.

20305724 is a deficient number, since it is larger than the sum of its proper divisors (15229300).

20305724 is a wasteful number, since it uses less digits than its factorization.

20305724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5076435 (or 5076433 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 23.

The square root of 20305724 is about 4506.1873019217. The cubic root of 20305724 is about 272.8178777882.

The spelling of 20305724 in words is "twenty million, three hundred five thousand, seven hundred twenty-four".