20392871491 has 2 divisors, whose sum is σ = 20392871492. Its totient is φ = 20392871490.

The previous prime is 20392871489. The next prime is 20392871497. The reversal of 20392871491 is 19417829302.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20392871491 - 2¹ = 20392871489 is a prime.

Together with 20392871489, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20392871497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10196435745 + 10196435746.

It is an arithmetic number, because the mean of its divisors is an integer number (10196435746).

Almost surely, 2^20392871491 is an apocalyptic number.

20392871491 is a deficient number, since it is larger than the sum of its proper divisors (1).

20392871491 is an equidigital number, since it uses as much as digits as its factorization.

20392871491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 217728, while the sum is 46.

The spelling of 20392871491 in words is "twenty billion, three hundred ninety-two million, eight hundred seventy-one thousand, four hundred ninety-one".