7212139 has 4 divisors (see below), whose sum is σ = 7867800. Its totient is φ = 6556480.

The previous prime is 7212083. The next prime is 7212157. The reversal of 7212139 is 9312127.

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

It is a cyclic number.

It is not a de Polignac number, because 7212139 - 2⁷ = 7212011 is a prime.

It is a Duffinian number.

7212139 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (7212169) 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, 327814 + ... + 327835.

It is an arithmetic number, because the mean of its divisors is an integer number (1966950).

Almost surely, 2^7212139 is an apocalyptic number.

7212139 is a deficient number, since it is larger than the sum of its proper divisors (655661).

7212139 is a wasteful number, since it uses less digits than its factorization.

7212139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 655660.

The product of its digits is 756, while the sum is 25.

The square root of 7212139 is about 2685.5425894966. The cubic root of 7212139 is about 193.2063352103.

The spelling of 7212139 in words is "seven million, two hundred twelve thousand, one hundred thirty-nine".