5991910921 has 2 divisors, whose sum is σ = 5991910922. Its totient is φ = 5991910920.

The previous prime is 5991910901. The next prime is 5991910997. The reversal of 5991910921 is 1290191995.

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., 3805039225 + 2186871696 = 61685^2 + 46764^2 .

It is a cyclic number.

It is not a de Polignac number, because 5991910921 - 2⁹ = 5991910409 is a prime.

It is not a weakly prime, because it can be changed into another prime (5991910901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2995955460 + 2995955461.

It is an arithmetic number, because the mean of its divisors is an integer number (2995955461).

Almost surely, 2^5991910921 is an apocalyptic number.

It is an amenable number.

5991910921 is a deficient number, since it is larger than the sum of its proper divisors (1).

5991910921 is an equidigital number, since it uses as much as digits as its factorization.

5991910921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 65610, while the sum is 46.

The square root of 5991910921 is about 77407.4345331248. The cubic root of 5991910921 is about 1816.3036238024.

The spelling of 5991910921 in words is "five billion, nine hundred ninety-one million, nine hundred ten thousand, nine hundred twenty-one".