72447621 has 4 divisors (see below), whose sum is σ = 96596832. Its totient is φ = 48298412.

The previous prime is 72447611. The next prime is 72447623. The reversal of 72447621 is 12674427.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12674427 = 3 ⋅4224809.

It is a cyclic number.

It is not a de Polignac number, because 72447621 - 2¹¹ = 72445573 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72447623) 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, 12074601 + ... + 12074606.

It is an arithmetic number, because the mean of its divisors is an integer number (24149208).

Almost surely, 2^72447621 is an apocalyptic number.

It is an amenable number.

72447621 is a deficient number, since it is larger than the sum of its proper divisors (24149211).

72447621 is a wasteful number, since it uses less digits than its factorization.

72447621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24149210.

The product of its digits is 18816, while the sum is 33.

The square root of 72447621 is about 8511.6168264320. The cubic root of 72447621 is about 416.8771037988.

The spelling of 72447621 in words is "seventy-two million, four hundred forty-seven thousand, six hundred twenty-one".