2661320401 has 4 divisors (see below), whose sum is σ = 2753090100. Its totient is φ = 2569550704.

The previous prime is 2661320393. The next prime is 2661320447. The reversal of 2661320401 is 1040231662.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1103834176 + 1557486225 = 33224^2 + 39465^2 .

It is a cyclic number.

It is not a de Polignac number, because 2661320401 - 2³ = 2661320393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2661320801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45884806 + ... + 45884863.

It is an arithmetic number, because the mean of its divisors is an integer number (688272525).

Almost surely, 2^2661320401 is an apocalyptic number.

It is an amenable number.

2661320401 is a deficient number, since it is larger than the sum of its proper divisors (91769699).

2661320401 is an equidigital number, since it uses as much as digits as its factorization.

2661320401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91769698.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 2661320401 is about 51587.9869834054. The cubic root of 2661320401 is about 1385.7952053030.

The spelling of 2661320401 in words is "two billion, six hundred sixty-one million, three hundred twenty thousand, four hundred one".