40289921 has 16 divisors (see below), whose sum is σ = 47792640. Its totient is φ = 33246720.

The previous prime is 40289891. The next prime is 40289923. The reversal of 40289921 is 12998204.

It is a cyclic number.

It is not a de Polignac number, because 40289921 - 2¹⁴ = 40273537 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (40289923) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 21785 + ... + 23561.

It is an arithmetic number, because the mean of its divisors is an integer number (2987040).

Almost surely, 2^40289921 is an apocalyptic number.

40289921 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

It is an amenable number.

40289921 is a deficient number, since it is larger than the sum of its proper divisors (7502719).

40289921 is a wasteful number, since it uses less digits than its factorization.

40289921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1904.

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 40289921 is about 6347.4342060395. The cubic root of 40289921 is about 342.8194643036.

The spelling of 40289921 in words is "forty million, two hundred eighty-nine thousand, nine hundred twenty-one".