15640039 has 2 divisors, whose sum is σ = 15640040. Its totient is φ = 15640038.

The previous prime is 15639997. The next prime is 15640063. The reversal of 15640039 is 93004651.

It is a strong prime.

It is an emirp because it is prime and its reverse (93004651) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 15640039 - 2¹¹ = 15637991 is a prime.

It is a super-2 number, since 2×15640039² = 489221639843042, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 15639989 and 15640016.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15640139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7820019 + 7820020.

It is an arithmetic number, because the mean of its divisors is an integer number (7820020).

Almost surely, 2^15640039 is an apocalyptic number.

15640039 is a deficient number, since it is larger than the sum of its proper divisors (1).

15640039 is an equidigital number, since it uses as much as digits as its factorization.

15640039 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 15640039 is about 3954.7489174409. The cubic root of 15640039 is about 250.0801822805.

The spelling of 15640039 in words is "fifteen million, six hundred forty thousand, thirty-nine".