1979921401 has 4 divisors (see below), whose sum is σ = 1982026404. Its totient is φ = 1977816400.

The previous prime is 1979921357. The next prime is 1979921431. The reversal of 1979921401 is 1041299791.

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 409860025 + 1570061376 = 20245^2 + 39624^2 .

It is a cyclic number.

It is not a de Polignac number, because 1979921401 - 2⁹ = 1979920889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1979921431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1051090 + ... + 1052971.

It is an arithmetic number, because the mean of its divisors is an integer number (495506601).

Almost surely, 2^1979921401 is an apocalyptic number.

It is an amenable number.

1979921401 is a deficient number, since it is larger than the sum of its proper divisors (2105003).

1979921401 is an equidigital number, since it uses as much as digits as its factorization.

1979921401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2105002.

The product of its (nonzero) digits is 40824, while the sum is 43.

The square root of 1979921401 is about 44496.3077232258. The cubic root of 1979921401 is about 1255.6906197114.

The spelling of 1979921401 in words is "one billion, nine hundred seventy-nine million, nine hundred twenty-one thousand, four hundred one".