43487021 has 4 divisors (see below), whose sum is σ = 43502844. Its totient is φ = 43471200.

The previous prime is 43486999. The next prime is 43487023. The reversal of 43487021 is 12078434.

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

It can be written as a sum of positive squares in 2 ways, for example, as 29008996 + 14478025 = 5386^2 + 3805^2 .

It is a cyclic number.

It is not a de Polignac number, because 43487021 - 2¹⁰ = 43485997 is a prime.

It is a super-2 number, since 2×43487021² = 3782241990908882, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43487023) 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, 2600 + ... + 9681.

It is an arithmetic number, because the mean of its divisors is an integer number (10875711).

Almost surely, 2^43487021 is an apocalyptic number.

It is an amenable number.

43487021 is a deficient number, since it is larger than the sum of its proper divisors (15823).

43487021 is a wasteful number, since it uses less digits than its factorization.

43487021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15822.

The product of its (nonzero) digits is 5376, while the sum is 29.

The square root of 43487021 is about 6594.4689702811. The cubic root of 43487021 is about 351.6575014145.

The spelling of 43487021 in words is "forty-three million, four hundred eighty-seven thousand, twenty-one".