39978454 has 4 divisors (see below), whose sum is σ = 59967684. Its totient is φ = 19989226.

The previous prime is 39978409. The next prime is 39978473. The reversal of 39978454 is 45487993.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 45487993 = 103 ⋅441631.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 39978398 and 39978407.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9994612 + ... + 9994615.

It is an arithmetic number, because the mean of its divisors is an integer number (14991921).

Almost surely, 2^39978454 is an apocalyptic number.

39978454 is a deficient number, since it is larger than the sum of its proper divisors (19989230).

39978454 is a wasteful number, since it uses less digits than its factorization.

39978454 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19989229.

The product of its digits is 1088640, while the sum is 49.

The square root of 39978454 is about 6322.8517300345. The cubic root of 39978454 is about 341.9337730705.

The spelling of 39978454 in words is "thirty-nine million, nine hundred seventy-eight thousand, four hundred fifty-four".