43742021 has 8 divisors (see below), whose sum is σ = 45831744. Its totient is φ = 41668000.

The previous prime is 43742011. The next prime is 43742057. The reversal of 43742021 is 12024734.

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 43742021 - 2¹⁰ = 43740997 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43742011) 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, 1985 + ... + 9561.

It is an arithmetic number, because the mean of its divisors is an integer number (5728968).

Almost surely, 2^43742021 is an apocalyptic number.

It is an amenable number.

43742021 is a deficient number, since it is larger than the sum of its proper divisors (2089723).

43742021 is a wasteful number, since it uses less digits than its factorization.

43742021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7851.

The product of its (nonzero) digits is 1344, while the sum is 23.

The square root of 43742021 is about 6613.7750944525. The cubic root of 43742021 is about 352.3435141974.

Adding to 43742021 its reverse (12024734), we get a palindrome (55766755).

The spelling of 43742021 in words is "forty-three million, seven hundred forty-two thousand, twenty-one".