19640660401 has 2 divisors, whose sum is σ = 19640660402. Its totient is φ = 19640660400.

The previous prime is 19640660357. The next prime is 19640660407. The reversal of 19640660401 is 10406604691.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19209682801 + 430977600 = 138599^2 + 20760^2 .

It is a cyclic number.

It is not a de Polignac number, because 19640660401 - 2¹³ = 19640652209 is a prime.

It is not a weakly prime, because it can be changed into another prime (19640660407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9820330200 + 9820330201.

It is an arithmetic number, because the mean of its divisors is an integer number (9820330201).

Almost surely, 2^19640660401 is an apocalyptic number.

It is an amenable number.

19640660401 is a deficient number, since it is larger than the sum of its proper divisors (1).

19640660401 is an equidigital number, since it uses as much as digits as its factorization.

19640660401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 37.

The spelling of 19640660401 in words is "nineteen billion, six hundred forty million, six hundred sixty thousand, four hundred one".