20899562077 has 2 divisors, whose sum is σ = 20899562078. Its totient is φ = 20899562076.

The previous prime is 20899562039. The next prime is 20899562111. The reversal of 20899562077 is 77026599802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17492972121 + 3406589956 = 132261^2 + 58366^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20899562077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20899562377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10449781038 + 10449781039.

It is an arithmetic number, because the mean of its divisors is an integer number (10449781039).

Almost surely, 2^20899562077 is an apocalyptic number.

It is an amenable number.

20899562077 is a deficient number, since it is larger than the sum of its proper divisors (1).

20899562077 is an equidigital number, since it uses as much as digits as its factorization.

20899562077 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3810240, while the sum is 55.

The spelling of 20899562077 in words is "twenty billion, eight hundred ninety-nine million, five hundred sixty-two thousand, seventy-seven".