4389377921 has 2 divisors, whose sum is σ = 4389377922. Its totient is φ = 4389377920.

The previous prime is 4389377899. The next prime is 4389377933. The reversal of 4389377921 is 1297739834.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4264743025 + 124634896 = 65305^2 + 11164^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-4389377921 is a prime.

It is not a weakly prime, because it can be changed into another prime (4389377981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2194688960 + 2194688961.

It is an arithmetic number, because the mean of its divisors is an integer number (2194688961).

Almost surely, 2^4389377921 is an apocalyptic number.

It is an amenable number.

4389377921 is a deficient number, since it is larger than the sum of its proper divisors (1).

4389377921 is an equidigital number, since it uses as much as digits as its factorization.

4389377921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2286144, while the sum is 53.

The square root of 4389377921 is about 66252.3804930812. The cubic root of 4389377921 is about 1637.3228581837.

The spelling of 4389377921 in words is "four billion, three hundred eighty-nine million, three hundred seventy-seven thousand, nine hundred twenty-one".