20400155047 has 2 divisors, whose sum is σ = 20400155048. Its totient is φ = 20400155046.

The previous prime is 20400154993. The next prime is 20400155051. The reversal of 20400155047 is 74055100402.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20400155047 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20400155147) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10200077523 + 10200077524.

It is an arithmetic number, because the mean of its divisors is an integer number (10200077524).

Almost surely, 2^20400155047 is an apocalyptic number.

20400155047 is a deficient number, since it is larger than the sum of its proper divisors (1).

20400155047 is an equidigital number, since it uses as much as digits as its factorization.

20400155047 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5600, while the sum is 28.

Adding to 20400155047 its reverse (74055100402), we get a palindrome (94455255449).

The spelling of 20400155047 in words is "twenty billion, four hundred million, one hundred fifty-five thousand, forty-seven".