20715091 has 2 divisors, whose sum is σ = 20715092. Its totient is φ = 20715090.

The previous prime is 20715067. The next prime is 20715113. The reversal of 20715091 is 19051702.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20715091 - 2⁵ = 20715059 is a prime.

It is a super-2 number, since 2×20715091² = 858229990276562, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20715041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10357545 + 10357546.

It is an arithmetic number, because the mean of its divisors is an integer number (10357546).

Almost surely, 2^20715091 is an apocalyptic number.

20715091 is a deficient number, since it is larger than the sum of its proper divisors (1).

20715091 is an equidigital number, since it uses as much as digits as its factorization.

20715091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 630, while the sum is 25.

The square root of 20715091 is about 4551.3834160615. The cubic root of 20715091 is about 274.6390459927.

Adding to 20715091 its reverse (19051702), we get a palindrome (39766793).

The spelling of 20715091 in words is "twenty million, seven hundred fifteen thousand, ninety-one".