39749991 has 4 divisors (see below), whose sum is σ = 52999992. Its totient is φ = 26499992.

The previous prime is 39749971. The next prime is 39750013. The reversal of 39749991 is 19994793.

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 39749991 - 2¹⁷ = 39618919 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39749971) 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, 6624996 + ... + 6625001.

It is an arithmetic number, because the mean of its divisors is an integer number (13249998).

Almost surely, 2^39749991 is an apocalyptic number.

39749991 is a deficient number, since it is larger than the sum of its proper divisors (13250001).

39749991 is a wasteful number, since it uses less digits than its factorization.

39749991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13250000.

The product of its digits is 551124, while the sum is 51.

The square root of 39749991 is about 6304.7593927128. The cubic root of 39749991 is about 341.2811840708.

The spelling of 39749991 in words is "thirty-nine million, seven hundred forty-nine thousand, nine hundred ninety-one".