20495639 has 2 divisors, whose sum is σ = 20495640. Its totient is φ = 20495638.

The previous prime is 20495633. The next prime is 20495647. The reversal of 20495639 is 93659402.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20495639 - 2⁸ = 20495383 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20495633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10247819 + 10247820.

It is an arithmetic number, because the mean of its divisors is an integer number (10247820).

Almost surely, 2^20495639 is an apocalyptic number.

20495639 is a deficient number, since it is larger than the sum of its proper divisors (1).

20495639 is an equidigital number, since it uses as much as digits as its factorization.

20495639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 58320, while the sum is 38.

The square root of 20495639 is about 4527.2109515683. The cubic root of 20495639 is about 273.6657751915.

The spelling of 20495639 in words is "twenty million, four hundred ninety-five thousand, six hundred thirty-nine".