39640955691 has 16 divisors (see below), whose sum is σ = 58909161600. Its totient is φ = 23563663488.

The previous prime is 39640955689. The next prime is 39640955693. The reversal of 39640955691 is 19655904693.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (39640955689) and next prime (39640955693).

It is not a de Polignac number, because 39640955691 - 2¹ = 39640955689 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is not an unprimeable number, because it can be changed into a prime (39640955693) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20453601 + ... + 20455538.

It is an arithmetic number, because the mean of its divisors is an integer number (3681822600).

Almost surely, 2^39640955691 is an apocalyptic number.

39640955691 is a deficient number, since it is larger than the sum of its proper divisors (19268205909).

39640955691 is a wasteful number, since it uses less digits than its factorization.

39640955691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40909178.

The product of its (nonzero) digits is 7873200, while the sum is 57.

The spelling of 39640955691 in words is "thirty-nine billion, six hundred forty million, nine hundred fifty-five thousand, six hundred ninety-one".