20657221607707 has 2 divisors, whose sum is σ = 20657221607708. Its totient is φ = 20657221607706.

The previous prime is 20657221607699. The next prime is 20657221607713. The reversal of 20657221607707 is 70770612275602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20657221607707 - 2³ = 20657221607699 is a prime.

It is not a weakly prime, because it can be changed into another prime (20657221602707) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10328610803853 + 10328610803854.

It is an arithmetic number, because the mean of its divisors is an integer number (10328610803854).

Almost surely, 2^{20657221607707} is an apocalyptic number.

20657221607707 is a deficient number, since it is larger than the sum of its proper divisors (1).

20657221607707 is an equidigital number, since it uses as much as digits as its factorization.

20657221607707 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3457440, while the sum is 52.

The spelling of 20657221607707 in words is "twenty trillion, six hundred fifty-seven billion, two hundred twenty-one million, six hundred seven thousand, seven hundred seven".