40689979 has 4 divisors (see below), whose sum is σ = 44389080. Its totient is φ = 36990880.

The previous prime is 40689953. The next prime is 40689983. The reversal of 40689979 is 97998604.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 40689979 - 2¹³ = 40681787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40686979) 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, 1849534 + ... + 1849555.

It is an arithmetic number, because the mean of its divisors is an integer number (11097270).

Almost surely, 2^40689979 is an apocalyptic number.

40689979 is a deficient number, since it is larger than the sum of its proper divisors (3699101).

40689979 is a wasteful number, since it uses less digits than its factorization.

40689979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3699100.

The product of its (nonzero) digits is 979776, while the sum is 52.

The square root of 40689979 is about 6378.8697274674. The cubic root of 40689979 is about 343.9504024176.

The spelling of 40689979 in words is "forty million, six hundred eighty-nine thousand, nine hundred seventy-nine".