20456400389 has 2 divisors, whose sum is σ = 20456400390. Its totient is φ = 20456400388.

The previous prime is 20456400359. The next prime is 20456400421. The reversal of 20456400389 is 98300465402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18616419364 + 1839981025 = 136442^2 + 42895^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20456400389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20456400329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10228200194 + 10228200195.

It is an arithmetic number, because the mean of its divisors is an integer number (10228200195).

Almost surely, 2^20456400389 is an apocalyptic number.

It is an amenable number.

20456400389 is a deficient number, since it is larger than the sum of its proper divisors (1).

20456400389 is an equidigital number, since it uses as much as digits as its factorization.

20456400389 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 207360, while the sum is 41.

The spelling of 20456400389 in words is "twenty billion, four hundred fifty-six million, four hundred thousand, three hundred eighty-nine".