212740091 has 4 divisors (see below), whose sum is σ = 225254232. Its totient is φ = 200225952.

The previous prime is 212740081. The next prime is 212740097. The reversal of 212740091 is 190047212.

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 212740091 - 2²² = 208545787 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 212740091.

It is not an unprimeable number, because it can be changed into a prime (212740097) 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, 6257045 + ... + 6257078.

It is an arithmetic number, because the mean of its divisors is an integer number (56313558).

Almost surely, 2^212740091 is an apocalyptic number.

212740091 is a deficient number, since it is larger than the sum of its proper divisors (12514141).

212740091 is a wasteful number, since it uses less digits than its factorization.

212740091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12514140.

The product of its (nonzero) digits is 1008, while the sum is 26.

The square root of 212740091 is about 14585.6124657143. The cubic root of 212740091 is about 596.9662522180.

The spelling of 212740091 in words is "two hundred twelve million, seven hundred forty thousand, ninety-one".