42744021 has 8 divisors (see below), whose sum is σ = 58317600. Its totient is φ = 27833232.

The previous prime is 42744019. The next prime is 42744049. The reversal of 42744021 is 12044724.

42744021 = 120² + 121² + ... + 506².

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

It is not a de Polignac number, because 42744021 - 2¹ = 42744019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 42743982 and 42744000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42744011) 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, 165546 + ... + 165803.

It is an arithmetic number, because the mean of its divisors is an integer number (7289700).

Almost surely, 2^42744021 is an apocalyptic number.

It is an amenable number.

42744021 is a deficient number, since it is larger than the sum of its proper divisors (15573579).

42744021 is a wasteful number, since it uses less digits than its factorization.

42744021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331395.

The product of its (nonzero) digits is 1792, while the sum is 24.

The square root of 42744021 is about 6537.8911737654. The cubic root of 42744021 is about 349.6432310125.

Adding to 42744021 its reverse (12044724), we get a palindrome (54788745).

The spelling of 42744021 in words is "forty-two million, seven hundred forty-four thousand, twenty-one".