39978489 has 8 divisors (see below), whose sum is σ = 56110240. Its totient is φ = 25249536.

The previous prime is 39978487. The next prime is 39978493. The reversal of 39978489 is 98487993.

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

It is not a de Polignac number, because 39978489 - 2¹ = 39978487 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57), and also a Moran number because the ratio is a prime number: 701377 = 39978489 / (3 + 9 + 9 + 7 + 8 + 4 + 8 + 9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39978481) 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, 350632 + ... + 350745.

It is an arithmetic number, because the mean of its divisors is an integer number (7013780).

Almost surely, 2^39978489 is an apocalyptic number.

It is an amenable number.

39978489 is a deficient number, since it is larger than the sum of its proper divisors (16131751).

39978489 is a wasteful number, since it uses less digits than its factorization.

39978489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 701399.

The product of its digits is 3919104, while the sum is 57.

The square root of 39978489 is about 6322.8544977723. The cubic root of 39978489 is about 341.9338728549.

The spelling of 39978489 in words is "thirty-nine million, nine hundred seventy-eight thousand, four hundred eighty-nine".