20315655991 has 2 divisors, whose sum is σ = 20315655992. Its totient is φ = 20315655990.

The previous prime is 20315655977. The next prime is 20315656003. The reversal of 20315655991 is 19955651302.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20315655991 - 2⁷ = 20315655863 is a prime.

It is a super-3 number, since 3×20315655991³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20315685991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10157827995 + 10157827996.

It is an arithmetic number, because the mean of its divisors is an integer number (10157827996).

Almost surely, 2^20315655991 is an apocalyptic number.

20315655991 is a deficient number, since it is larger than the sum of its proper divisors (1).

20315655991 is an equidigital number, since it uses as much as digits as its factorization.

20315655991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 364500, while the sum is 46.

The spelling of 20315655991 in words is "twenty billion, three hundred fifteen million, six hundred fifty-five thousand, nine hundred ninety-one".