20351217925391 has 2 divisors, whose sum is σ = 20351217925392. Its totient is φ = 20351217925390.

The previous prime is 20351217925369. The next prime is 20351217925397. The reversal of 20351217925391 is 19352971215302.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20351217925391 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20351217925397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10175608962695 + 10175608962696.

It is an arithmetic number, because the mean of its divisors is an integer number (10175608962696).

Almost surely, 2^{20351217925391} is an apocalyptic number.

20351217925391 is a deficient number, since it is larger than the sum of its proper divisors (1).

20351217925391 is an equidigital number, since it uses as much as digits as its factorization.

20351217925391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1020600, while the sum is 50.

The spelling of 20351217925391 in words is "twenty trillion, three hundred fifty-one billion, two hundred seventeen million, nine hundred twenty-five thousand, three hundred ninety-one".