43153981 has 6 divisors (see below), whose sum is σ = 46729050. Its totient is φ = 39834288.

The previous prime is 43153937. The next prime is 43153991. The reversal of 43153981 is 18935134.

It can be written as a sum of positive squares in 3 ways, for example, as 5331481 + 37822500 = 2309^2 + 6150^2 .

It is not a de Polignac number, because 43153981 - 2²³ = 34765373 is a prime.

It is a super-2 number, since 2×43153981² = 3724532152296722, 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 (43153991) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 127506 + ... + 127843.

It is an arithmetic number, because the mean of its divisors is an integer number (7788175).

Almost surely, 2^43153981 is an apocalyptic number.

It is an amenable number.

43153981 is a deficient number, since it is larger than the sum of its proper divisors (3575069).

43153981 is a wasteful number, since it uses less digits than its factorization.

43153981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255375 (or 255362 counting only the distinct ones).

The product of its digits is 12960, while the sum is 34.

The square root of 43153981 is about 6569.1689733177. The cubic root of 43153981 is about 350.7574913810.

The spelling of 43153981 in words is "forty-three million, one hundred fifty-three thousand, nine hundred eighty-one".