20315655977 has 2 divisors, whose sum is σ = 20315655978. Its totient is φ = 20315655976.

The previous prime is 20315655967. The next prime is 20315655991. The reversal of 20315655977 is 77955651302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14057422096 + 6258233881 = 118564^2 + 79109^2 .

It is a cyclic number.

It is not a de Polignac number, because 20315655977 - 2¹⁴ = 20315639593 is a prime.

It is not a weakly prime, because it can be changed into another prime (20315655907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10157827988 + 10157827989.

It is an arithmetic number, because the mean of its divisors is an integer number (10157827989).

Almost surely, 2^20315655977 is an apocalyptic number.

It is an amenable number.

20315655977 is a deficient number, since it is larger than the sum of its proper divisors (1).

20315655977 is an equidigital number, since it uses as much as digits as its factorization.

20315655977 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1984500, while the sum is 50.

The spelling of 20315655977 in words is "twenty billion, three hundred fifteen million, six hundred fifty-five thousand, nine hundred seventy-seven".