3999293621 has 2 divisors, whose sum is σ = 3999293622. Its totient is φ = 3999293620.

The previous prime is 3999293593. The next prime is 3999293657. The reversal of 3999293621 is 1263929993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3999171121 + 122500 = 63239^2 + 350^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3999293621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3999293671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1999646810 + 1999646811.

It is an arithmetic number, because the mean of its divisors is an integer number (1999646811).

Almost surely, 2^3999293621 is an apocalyptic number.

It is an amenable number.

3999293621 is a deficient number, since it is larger than the sum of its proper divisors (1).

3999293621 is an equidigital number, since it uses as much as digits as its factorization.

3999293621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1417176, while the sum is 53.

The square root of 3999293621 is about 63239.9685404729. The cubic root of 3999293621 is about 1587.3076042365.

The spelling of 3999293621 in words is "three billion, nine hundred ninety-nine million, two hundred ninety-three thousand, six hundred twenty-one".