40019639 has 4 divisors (see below), whose sum is σ = 43657800. Its totient is φ = 36381480.

The previous prime is 40019633. The next prime is 40019659. The reversal of 40019639 is 93691004.

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 40019639 - 2¹² = 40015543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40019633) 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, 1819064 + ... + 1819085.

It is an arithmetic number, because the mean of its divisors is an integer number (10914450).

Almost surely, 2^40019639 is an apocalyptic number.

40019639 is a deficient number, since it is larger than the sum of its proper divisors (3638161).

40019639 is a wasteful number, since it uses less digits than its factorization.

40019639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3638160.

The product of its (nonzero) digits is 5832, while the sum is 32.

The square root of 40019639 is about 6326.1077290859. The cubic root of 40019639 is about 342.0511505405.

The spelling of 40019639 in words is "forty million, nineteen thousand, six hundred thirty-nine".