20400403591 has 2 divisors, whose sum is σ = 20400403592. Its totient is φ = 20400403590.

The previous prime is 20400403577. The next prime is 20400403601. The reversal of 20400403591 is 19530400402.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20400403591 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20400407591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10200201795 + 10200201796.

It is an arithmetic number, because the mean of its divisors is an integer number (10200201796).

Almost surely, 2^20400403591 is an apocalyptic number.

20400403591 is a deficient number, since it is larger than the sum of its proper divisors (1).

20400403591 is an equidigital number, since it uses as much as digits as its factorization.

20400403591 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 28.

Adding to 20400403591 its reverse (19530400402), we get a palindrome (39930803993).

The spelling of 20400403591 in words is "twenty billion, four hundred million, four hundred three thousand, five hundred ninety-one".