39953991 has 32 divisors (see below), whose sum is σ = 66774528. Its totient is φ = 20643840.

The previous prime is 39953987. The next prime is 39953993. The reversal of 39953991 is 19935993.

It is a happy number.

It is not a de Polignac number, because 39953991 - 2² = 39953987 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 39953991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39953993) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 59031 + ... + 59703.

It is an arithmetic number, because the mean of its divisors is an integer number (2086704).

Almost surely, 2^39953991 is an apocalyptic number.

39953991 is a deficient number, since it is larger than the sum of its proper divisors (26820537).

39953991 is a wasteful number, since it uses less digits than its factorization.

39953991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 951.

The product of its digits is 295245, while the sum is 48.

The square root of 39953991 is about 6320.9169429759. The cubic root of 39953991 is about 341.8640152237.

The spelling of 39953991 in words is "thirty-nine million, nine hundred fifty-three thousand, nine hundred ninety-one".