40021090 has 8 divisors (see below), whose sum is σ = 72037980. Its totient is φ = 16008432.

The previous prime is 40021061. The next prime is 40021117. The reversal of 40021090 is 9012004.

It can be written as a sum of positive squares in 2 ways, for example, as 39955041 + 66049 = 6321^2 + 257^2 .

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

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 in 3 ways as a sum of consecutive naturals, for example, 2001045 + ... + 2001064.

Almost surely, 2^40021090 is an apocalyptic number.

40021090 is a deficient number, since it is larger than the sum of its proper divisors (32016890).

40021090 is a wasteful number, since it uses less digits than its factorization.

40021090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4002116.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 40021090 is about 6326.2224115186. Note that the first 3 decimals coincide. The cubic root of 40021090 is about 342.0552844294.

Adding to 40021090 its reverse (9012004), we get a palindrome (49033094).

The spelling of 40021090 in words is "forty million, twenty-one thousand, ninety".