20400442423993 has 2 divisors, whose sum is σ = 20400442423994. Its totient is φ = 20400442423992.

The previous prime is 20400442423973. The next prime is 20400442424107. The reversal of 20400442423993 is 39932424400402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19591671357504 + 808771066489 = 4426248^2 + 899317^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20400442423993 is a prime.

It is not a weakly prime, because it can be changed into another prime (20400442423973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10200221211996 + 10200221211997.

It is an arithmetic number, because the mean of its divisors is an integer number (10200221211997).

Almost surely, 2^{20400442423993} is an apocalyptic number.

It is an amenable number.

20400442423993 is a deficient number, since it is larger than the sum of its proper divisors (1).

20400442423993 is an equidigital number, since it uses as much as digits as its factorization.

20400442423993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1492992, while the sum is 46.

The spelling of 20400442423993 in words is "twenty trillion, four hundred billion, four hundred forty-two million, four hundred twenty-three thousand, nine hundred ninety-three".