20415135991 has 2 divisors, whose sum is σ = 20415135992. Its totient is φ = 20415135990.

The previous prime is 20415135973. The next prime is 20415136019. The reversal of 20415135991 is 19953151402.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20415135991 - 2⁹ = 20415135479 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20415135971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10207567995 + 10207567996.

It is an arithmetic number, because the mean of its divisors is an integer number (10207567996).

Almost surely, 2^20415135991 is an apocalyptic number.

20415135991 is a deficient number, since it is larger than the sum of its proper divisors (1).

20415135991 is an equidigital number, since it uses as much as digits as its factorization.

20415135991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48600, while the sum is 40.

The spelling of 20415135991 in words is "twenty billion, four hundred fifteen million, one hundred thirty-five thousand, nine hundred ninety-one".