72210121 has 4 divisors (see below), whose sum is σ = 73287952. Its totient is φ = 71132292.

The previous prime is 72210077. The next prime is 72210137. The reversal of 72210121 is 12101227.

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 72210121 - 2⁹ = 72209609 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 72210095 and 72210104.

It is not an unprimeable number, because it can be changed into a prime (72210181) 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, 538815 + ... + 538948.

It is an arithmetic number, because the mean of its divisors is an integer number (18321988).

Almost surely, 2^72210121 is an apocalyptic number.

It is an amenable number.

72210121 is a deficient number, since it is larger than the sum of its proper divisors (1077831).

72210121 is a wasteful number, since it uses less digits than its factorization.

72210121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1077830.

The product of its (nonzero) digits is 56, while the sum is 16.

The square root of 72210121 is about 8497.6538526819. The cubic root of 72210121 is about 416.4210653582.

Adding to 72210121 its reverse (12101227), we get a palindrome (84311348).

The spelling of 72210121 in words is "seventy-two million, two hundred ten thousand, one hundred twenty-one".