20203639 has 2 divisors, whose sum is σ = 20203640. Its totient is φ = 20203638.

The previous prime is 20203621. The next prime is 20203643. The reversal of 20203639 is 93630202.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20203639 - 2¹³ = 20195447 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20206639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10101819 + 10101820.

It is an arithmetic number, because the mean of its divisors is an integer number (10101820).

Almost surely, 2^20203639 is an apocalyptic number.

20203639 is a deficient number, since it is larger than the sum of its proper divisors (1).

20203639 is an equidigital number, since it uses as much as digits as its factorization.

20203639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 25.

The square root of 20203639 is about 4494.8458260545. The cubic root of 20203639 is about 272.3599212714.

The spelling of 20203639 in words is "twenty million, two hundred three thousand, six hundred thirty-nine".