4021390997 has 8 divisors (see below), whose sum is σ = 4356356760. Its totient is φ = 3712051200.

The previous prime is 4021390979. The next prime is 4021391009. The reversal of 4021390997 is 7990931204.

It can be written as a sum of positive squares in 4 ways, for example, as 1236295921 + 2785095076 = 35161^2 + 52774^2 .

It is not a de Polignac number, because 4021390997 - 2²⁰ = 4020342421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4021395997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 913004 + ... + 917397.

It is an arithmetic number, because the mean of its divisors is an integer number (544544595).

Almost surely, 2^4021390997 is an apocalyptic number.

It is an amenable number.

4021390997 is a deficient number, since it is larger than the sum of its proper divisors (334965763).

4021390997 is an equidigital number, since it uses as much as digits as its factorization.

4021390997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1830440 (or 1830414 counting only the distinct ones).

The product of its (nonzero) digits is 122472, while the sum is 44.

The square root of 4021390997 is about 63414.4383953686. The cubic root of 4021390997 is about 1590.2256970332.

The spelling of 4021390997 in words is "four billion, twenty-one million, three hundred ninety thousand, nine hundred ninety-seven".