39991557 has 8 divisors (see below), whose sum is σ = 54226080. Its totient is φ = 26209040.

The previous prime is 39991547. The next prime is 39991573. The reversal of 39991557 is 75519993.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 39991557 - 2²² = 35797253 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39991537) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 112794 + ... + 113147.

It is an arithmetic number, because the mean of its divisors is an integer number (6778260).

Almost surely, 2^39991557 is an apocalyptic number.

It is an amenable number.

39991557 is a deficient number, since it is larger than the sum of its proper divisors (14234523).

39991557 is a wasteful number, since it uses less digits than its factorization.

39991557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226003.

The product of its digits is 382725, while the sum is 48.

The square root of 39991557 is about 6323.8878073540. The cubic root of 39991557 is about 341.9711254306.

The spelling of 39991557 in words is "thirty-nine million, nine hundred ninety-one thousand, five hundred fifty-seven".