20663739 has 6 divisors (see below), whose sum is σ = 29847636. Its totient is φ = 13775820.

The previous prime is 20663737. The next prime is 20663759. The reversal of 20663739 is 93736602.

It is not a de Polignac number, because 20663739 - 2¹ = 20663737 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20663737) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1147977 + ... + 1147994.

It is an arithmetic number, because the mean of its divisors is an integer number (4974606).

Almost surely, 2^20663739 is an apocalyptic number.

20663739 is a deficient number, since it is larger than the sum of its proper divisors (9183897).

20663739 is a wasteful number, since it uses less digits than its factorization.

20663739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2295977 (or 2295974 counting only the distinct ones).

The product of its (nonzero) digits is 40824, while the sum is 36.

The square root of 20663739 is about 4545.7385538546. The cubic root of 20663739 is about 274.4119179503.

The spelling of 20663739 in words is "twenty million, six hundred sixty-three thousand, seven hundred thirty-nine".