20456791 has 2 divisors, whose sum is σ = 20456792. Its totient is φ = 20456790.

The previous prime is 20456789. The next prime is 20456809. The reversal of 20456791 is 19765402.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20456791 - 2¹ = 20456789 is a prime.

Together with 20456789, it forms a pair of twin primes.

It is equal to p_1297690 and since 20456791 and 1297690 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20456771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10228395 + 10228396.

It is an arithmetic number, because the mean of its divisors is an integer number (10228396).

Almost surely, 2^20456791 is an apocalyptic number.

20456791 is a deficient number, since it is larger than the sum of its proper divisors (1).

20456791 is an equidigital number, since it uses as much as digits as its factorization.

20456791 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 20456791 is about 4522.9184162441. The cubic root of 20456791 is about 273.4927612784.

It can be divided in two parts, 2045 and 6791, that added together give a square (8836 = 94²).

The spelling of 20456791 in words is "twenty million, four hundred fifty-six thousand, seven hundred ninety-one".