20720943 has 12 divisors (see below), whose sum is σ = 31691088. Its totient is φ = 13001280.

The previous prime is 20720911. The next prime is 20720951. The reversal of 20720943 is 34902702.

It is not a de Polignac number, because 20720943 - 2⁵ = 20720911 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20720543) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 67563 + ... + 67868.

It is an arithmetic number, because the mean of its divisors is an integer number (2640924).

Almost surely, 2^20720943 is an apocalyptic number.

20720943 is a deficient number, since it is larger than the sum of its proper divisors (10970145).

20720943 is a wasteful number, since it uses less digits than its factorization.

20720943 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135454 (or 135451 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 27.

The square root of 20720943 is about 4552.0262521211. The cubic root of 20720943 is about 274.6649053429.

The spelling of 20720943 in words is "twenty million, seven hundred twenty thousand, nine hundred forty-three".