39978769 has 4 divisors (see below), whose sum is σ = 40003696. Its totient is φ = 39953844.

The previous prime is 39978749. The next prime is 39978779. The reversal of 39978769 is 96787993.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 39978769 - 2¹⁵ = 39946001 is a prime.

It is a super-2 number, since 2×39978769² = 3196603941510722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39978709) 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, 9879 + ... + 13324.

It is an arithmetic number, because the mean of its divisors is an integer number (10000924).

Almost surely, 2^39978769 is an apocalyptic number.

It is an amenable number.

39978769 is a deficient number, since it is larger than the sum of its proper divisors (24927).

39978769 is a wasteful number, since it uses less digits than its factorization.

39978769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24926.

The product of its digits is 5143824, while the sum is 58.

The square root of 39978769 is about 6322.8766396317. The cubic root of 39978769 is about 341.9346711280.

The spelling of 39978769 in words is "thirty-nine million, nine hundred seventy-eight thousand, seven hundred sixty-nine".