20783457 has 12 divisors (see below), whose sum is σ = 30086784. Its totient is φ = 13825080.

The previous prime is 20783437. The next prime is 20783479. The reversal of 20783457 is 75438702.

It is not a de Polignac number, because 20783457 - 2⁶ = 20783393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20783407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2232 + ... + 6822.

It is an arithmetic number, because the mean of its divisors is an integer number (2507232).

Almost surely, 2^20783457 is an apocalyptic number.

It is an amenable number.

20783457 is a deficient number, since it is larger than the sum of its proper divisors (9303327).

20783457 is a wasteful number, since it uses less digits than its factorization.

20783457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5100 (or 5097 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 36.

The square root of 20783457 is about 4558.8876932866. The cubic root of 20783457 is about 274.9408445762.

The spelling of 20783457 in words is "twenty million, seven hundred eighty-three thousand, four hundred fifty-seven".