43220731 has 4 divisors (see below), whose sum is σ = 43357392. Its totient is φ = 43084072.

The previous prime is 43220729. The next prime is 43220743. The reversal of 43220731 is 13702234.

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 43220731 - 2¹ = 43220729 is a prime.

It is a super-2 number, since 2×43220731² = 3736063176348722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (43220711) 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, 67855 + ... + 68488.

It is an arithmetic number, because the mean of its divisors is an integer number (10839348).

Almost surely, 2^43220731 is an apocalyptic number.

43220731 is a deficient number, since it is larger than the sum of its proper divisors (136661).

43220731 is a wasteful number, since it uses less digits than its factorization.

43220731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136660.

The product of its (nonzero) digits is 1008, while the sum is 22.

The square root of 43220731 is about 6574.2475615085. The cubic root of 43220731 is about 350.9382472131.

Adding to 43220731 its reverse (13702234), we get a palindrome (56922965).

The spelling of 43220731 in words is "forty-three million, two hundred twenty thousand, seven hundred thirty-one".