2145989971 has 2 divisors, whose sum is σ = 2145989972. Its totient is φ = 2145989970.

The previous prime is 2145989947. The next prime is 2145989977. The reversal of 2145989971 is 1799895412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2145989971 - 2²⁹ = 1609119059 is a prime.

It is not a weakly prime, because it can be changed into another prime (2145989977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1072994985 + 1072994986.

It is an arithmetic number, because the mean of its divisors is an integer number (1072994986).

Almost surely, 2^2145989971 is an apocalyptic number.

2145989971 is a deficient number, since it is larger than the sum of its proper divisors (1).

2145989971 is an equidigital number, since it uses as much as digits as its factorization.

2145989971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1632960, while the sum is 55.

The square root of 2145989971 is about 46324.8310412461. The cubic root of 2145989971 is about 1289.8599633658.

The spelling of 2145989971 in words is "two billion, one hundred forty-five million, nine hundred eighty-nine thousand, nine hundred seventy-one".