4309391981 has 4 divisors (see below), whose sum is σ = 4310139132. Its totient is φ = 4308644832.

The previous prime is 4309391963. The next prime is 4309391993. The reversal of 4309391981 is 1891939034.

4309391981 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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 3939445225 + 369946756 = 62765^2 + 19234^2 .

It is a cyclic number.

It is not a de Polignac number, because 4309391981 - 2⁶ = 4309391917 is a prime.

It is a super-2 number, since 2×4309391981² = 37141718491814208722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4309399981) 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, 364856 + ... + 376481.

It is an arithmetic number, because the mean of its divisors is an integer number (1077534783).

Almost surely, 2^4309391981 is an apocalyptic number.

It is an amenable number.

4309391981 is a deficient number, since it is larger than the sum of its proper divisors (747151).

4309391981 is an equidigital number, since it uses as much as digits as its factorization.

4309391981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 747150.

The product of its (nonzero) digits is 209952, while the sum is 47.

The square root of 4309391981 is about 65645.9593653715. The cubic root of 4309391981 is about 1627.3163942715.

The spelling of 4309391981 in words is "four billion, three hundred nine million, three hundred ninety-one thousand, nine hundred eighty-one".