19401788761 has 2 divisors, whose sum is σ = 19401788762. Its totient is φ = 19401788760.

The previous prime is 19401788701. The next prime is 19401788773. The reversal of 19401788761 is 16788710491.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14888636361 + 4513152400 = 122019^2 + 67180^2 .

It is a cyclic number.

It is not a de Polignac number, because 19401788761 - 2³¹ = 17254305113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19401788699 and 19401788708.

It is not a weakly prime, because it can be changed into another prime (19401788701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9700894380 + 9700894381.

It is an arithmetic number, because the mean of its divisors is an integer number (9700894381).

Almost surely, 2^19401788761 is an apocalyptic number.

It is an amenable number.

19401788761 is a deficient number, since it is larger than the sum of its proper divisors (1).

19401788761 is an equidigital number, since it uses as much as digits as its factorization.

19401788761 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 677376, while the sum is 52.

The spelling of 19401788761 in words is "nineteen billion, four hundred one million, seven hundred eighty-eight thousand, seven hundred sixty-one".