72550021 has 4 divisors (see below), whose sum is σ = 72575200. Its totient is φ = 72524844.

The previous prime is 72550019. The next prime is 72550031. The reversal of 72550021 is 12005527.

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 a cyclic number.

It is not a de Polignac number, because 72550021 - 2¹ = 72550019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 72549974 and 72550001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72550031) 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, 7611 + ... + 14248.

It is an arithmetic number, because the mean of its divisors is an integer number (18143800).

Almost surely, 2^72550021 is an apocalyptic number.

It is an amenable number.

72550021 is a deficient number, since it is larger than the sum of its proper divisors (25179).

72550021 is a wasteful number, since it uses less digits than its factorization.

72550021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25178.

The product of its (nonzero) digits is 700, while the sum is 22.

The square root of 72550021 is about 8517.6300107483. The cubic root of 72550021 is about 417.0734208910.

Adding to 72550021 its reverse (12005527), we get a palindrome (84555548).

The spelling of 72550021 in words is "seventy-two million, five hundred fifty thousand, twenty-one".