971621091 has 12 divisors (see below), whose sum is σ = 1603946032. Its totient is φ = 555212016.

The previous prime is 971621089. The next prime is 971621113. The reversal of 971621091 is 190126179.

It is not a de Polignac number, because 971621091 - 2¹ = 971621089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (971621051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7711216 + ... + 7711341.

Almost surely, 2^971621091 is an apocalyptic number.

971621091 is a deficient number, since it is larger than the sum of its proper divisors (632324941).

971621091 is a wasteful number, since it uses less digits than its factorization.

971621091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15422570 (or 15422567 counting only the distinct ones).

The product of its (nonzero) digits is 6804, while the sum is 36.

The square root of 971621091 is about 31170.8371879871. The cubic root of 971621091 is about 990.4494408658.

The spelling of 971621091 in words is "nine hundred seventy-one million, six hundred twenty-one thousand, ninety-one".