40021739 has 4 divisors (see below), whose sum is σ = 40570056. Its totient is φ = 39473424.

The previous prime is 40021727. The next prime is 40021747. The reversal of 40021739 is 93712004.

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 40021739 - 2⁸ = 40021483 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40021759) 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, 274049 + ... + 274194.

It is an arithmetic number, because the mean of its divisors is an integer number (10142514).

Almost surely, 2^40021739 is an apocalyptic number.

40021739 is a deficient number, since it is larger than the sum of its proper divisors (548317).

40021739 is an equidigital number, since it uses as much as digits as its factorization.

40021739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 548316.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 40021739 is about 6326.2737057450. The cubic root of 40021739 is about 342.0571333935.

The spelling of 40021739 in words is "forty million, twenty-one thousand, seven hundred thirty-nine".