72441021 has 4 divisors (see below), whose sum is σ = 96588032. Its totient is φ = 48294012.

The previous prime is 72441013. The next prime is 72441071. The reversal of 72441021 is 12014427.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 72441021 - 2³ = 72441013 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72441001) 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, 12073501 + ... + 12073506.

It is an arithmetic number, because the mean of its divisors is an integer number (24147008).

Almost surely, 2^72441021 is an apocalyptic number.

It is an amenable number.

72441021 is a deficient number, since it is larger than the sum of its proper divisors (24147011).

72441021 is a wasteful number, since it uses less digits than its factorization.

72441021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24147010.

The product of its (nonzero) digits is 448, while the sum is 21.

The square root of 72441021 is about 8511.2291121788. The cubic root of 72441021 is about 416.8644442046.

Adding to 72441021 its reverse (12014427), we get a palindrome (84455448).

The spelling of 72441021 in words is "seventy-two million, four hundred forty-one thousand, twenty-one".