1639972801 has 2 divisors, whose sum is σ = 1639972802. Its totient is φ = 1639972800.

The previous prime is 1639972781. The next prime is 1639972871. The reversal of 1639972801 is 1082799361.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1279922176 + 360050625 = 35776^2 + 18975^2 .

It is a cyclic number.

It is not a de Polignac number, because 1639972801 - 2¹³ = 1639964609 is a prime.

It is not a weakly prime, because it can be changed into another prime (1639972871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 819986400 + 819986401.

It is an arithmetic number, because the mean of its divisors is an integer number (819986401).

Almost surely, 2^1639972801 is an apocalyptic number.

It is an amenable number.

1639972801 is a deficient number, since it is larger than the sum of its proper divisors (1).

1639972801 is an equidigital number, since it uses as much as digits as its factorization.

1639972801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 163296, while the sum is 46.

The square root of 1639972801 is about 40496.5776455246. The cubic root of 1639972801 is about 1179.2671886358.

It can be divided in two parts, 163 and 9972801, that added together give a square (9972964 = 3158²).

The spelling of 1639972801 in words is "one billion, six hundred thirty-nine million, nine hundred seventy-two thousand, eight hundred one".