20613893491 has 2 divisors, whose sum is σ = 20613893492. Its totient is φ = 20613893490.

The previous prime is 20613893483. The next prime is 20613893537. The reversal of 20613893491 is 19439831602.

It is a happy number.

It is an a-pointer prime, because the next prime (20613893537) can be obtained adding 20613893491 to its sum of digits (46).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20613893491 - 2³ = 20613893483 is a prime.

It is not a weakly prime, because it can be changed into another prime (20613893431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10306946745 + 10306946746.

It is an arithmetic number, because the mean of its divisors is an integer number (10306946746).

Almost surely, 2^20613893491 is an apocalyptic number.

20613893491 is a deficient number, since it is larger than the sum of its proper divisors (1).

20613893491 is an equidigital number, since it uses as much as digits as its factorization.

20613893491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 279936, while the sum is 46.

The spelling of 20613893491 in words is "twenty billion, six hundred thirteen million, eight hundred ninety-three thousand, four hundred ninety-one".