97399991 has 4 divisors (see below), whose sum is σ = 104892312. Its totient is φ = 89907672.

The previous prime is 97399979. The next prime is 97399997. The reversal of 97399991 is 19999379.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 97399991 - 2⁶ = 97399927 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (97399997) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3746141 + ... + 3746166.

It is an arithmetic number, because the mean of its divisors is an integer number (26223078).

Almost surely, 2^97399991 is an apocalyptic number.

97399991 is a deficient number, since it is larger than the sum of its proper divisors (7492321).

97399991 is a wasteful number, since it uses less digits than its factorization.

97399991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7492320.

The product of its digits is 1240029, while the sum is 56.

The square root of 97399991 is about 9869.1433772136. The cubic root of 97399991 is about 460.1007828955.

The spelling of 97399991 in words is "ninety-seven million, three hundred ninety-nine thousand, nine hundred ninety-one".