72122261 has 4 divisors (see below), whose sum is σ = 72165612. Its totient is φ = 72078912.

The previous prime is 72122257. The next prime is 72122293. The reversal of 72122261 is 16222127.

It is a happy number.

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 59830225 + 12292036 = 7735^2 + 3506^2 .

It is a cyclic number.

It is not a de Polignac number, because 72122261 - 2² = 72122257 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 (72122221) 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, 19076 + ... + 22541.

It is an arithmetic number, because the mean of its divisors is an integer number (18041403).

Almost surely, 2^72122261 is an apocalyptic number.

It is an amenable number.

72122261 is a deficient number, since it is larger than the sum of its proper divisors (43351).

72122261 is a wasteful number, since it uses less digits than its factorization.

72122261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43350.

The product of its digits is 672, while the sum is 23.

The square root of 72122261 is about 8492.4826169972. The cubic root of 72122261 is about 416.2521065704.

Adding to 72122261 its reverse (16222127), we get a palindrome (88344388).

The spelling of 72122261 in words is "seventy-two million, one hundred twenty-two thousand, two hundred sixty-one".