43221981 has 8 divisors (see below), whose sum is σ = 62868384. Its totient is φ = 26195120.

The previous prime is 43221961. The next prime is 43222033. The reversal of 43221981 is 18912234.

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

It is a cyclic number.

It is not a de Polignac number, because 43221981 - 2⁶ = 43221917 is a prime.

It is a super-2 number, since 2×43221981² = 3736279283128722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43221931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 654846 + ... + 654911.

It is an arithmetic number, because the mean of its divisors is an integer number (7858548).

Almost surely, 2^43221981 is an apocalyptic number.

It is an amenable number.

43221981 is a deficient number, since it is larger than the sum of its proper divisors (19646403).

43221981 is a wasteful number, since it uses less digits than its factorization.

43221981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1309771.

The product of its digits is 3456, while the sum is 30.

The square root of 43221981 is about 6574.3426287348. The cubic root of 43221981 is about 350.9416303780.

The spelling of 43221981 in words is "forty-three million, two hundred twenty-one thousand, nine hundred eighty-one".