971621899 has 2 divisors, whose sum is σ = 971621900. Its totient is φ = 971621898.

The previous prime is 971621839. The next prime is 971621909. The reversal of 971621899 is 998126179.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 971621899 - 2¹¹ = 971619851 is a prime.

It is a super-2 number, since 2×971621899² = 1888098229232732402, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (971621839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 485810949 + 485810950.

It is an arithmetic number, because the mean of its divisors is an integer number (485810950).

Almost surely, 2^971621899 is an apocalyptic number.

971621899 is a deficient number, since it is larger than the sum of its proper divisors (1).

971621899 is an equidigital number, since it uses as much as digits as its factorization.

971621899 is an evil number, because the sum of its binary digits is even.

The product of its digits is 489888, while the sum is 52.

The square root of 971621899 is about 31170.8501488169. The cubic root of 971621899 is about 990.4497154183.

The spelling of 971621899 in words is "nine hundred seventy-one million, six hundred twenty-one thousand, eight hundred ninety-nine".