7572821 has 4 divisors (see below), whose sum is σ = 7586700. Its totient is φ = 7558944.

The previous prime is 7572793. The next prime is 7572833. The reversal of 7572821 is 1282757.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 470596 + 7102225 = 686^2 + 2665^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7572821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7572881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6086 + ... + 7223.

It is an arithmetic number, because the mean of its divisors is an integer number (1896675).

Almost surely, 2^7572821 is an apocalyptic number.

It is an amenable number.

7572821 is a deficient number, since it is larger than the sum of its proper divisors (13879).

7572821 is a wasteful number, since it uses less digits than its factorization.

7572821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13878.

The product of its digits is 7840, while the sum is 32.

The square root of 7572821 is about 2751.8759056324. The cubic root of 7572821 is about 196.3748639440.

Subtracting from 7572821 its reverse (1282757), we obtain a square (6290064 = 2508²).

The spelling of 7572821 in words is "seven million, five hundred seventy-two thousand, eight hundred twenty-one".