39697391 has 4 divisors (see below), whose sum is σ = 40977984. Its totient is φ = 38416800.

The previous prime is 39697387. The next prime is 39697409. The reversal of 39697391 is 19379693.

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 39697391 - 2² = 39697387 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 (39697331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 640250 + ... + 640311.

It is an arithmetic number, because the mean of its divisors is an integer number (10244496).

Almost surely, 2^39697391 is an apocalyptic number.

39697391 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

39697391 is a deficient number, since it is larger than the sum of its proper divisors (1280593).

39697391 is a wasteful number, since it uses less digits than its factorization.

39697391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1280592.

The product of its digits is 275562, while the sum is 47.

The square root of 39697391 is about 6300.5865599958. The cubic root of 39697391 is about 341.1305818204.

The spelling of 39697391 in words is "thirty-nine million, six hundred ninety-seven thousand, three hundred ninety-one".