212123091 has 4 divisors (see below), whose sum is σ = 282830792. Its totient is φ = 141415392.

The previous prime is 212123083. The next prime is 212123117. The reversal of 212123091 is 190321212.

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

It is not a de Polignac number, because 212123091 - 2³ = 212123083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (212123071) 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, 35353846 + ... + 35353851.

It is an arithmetic number, because the mean of its divisors is an integer number (70707698).

Almost surely, 2^212123091 is an apocalyptic number.

212123091 is a deficient number, since it is larger than the sum of its proper divisors (70707701).

212123091 is an equidigital number, since it uses as much as digits as its factorization.

212123091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70707700.

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 212123091 is about 14564.4461274708. The cubic root of 212123091 is about 596.3885757485.

The spelling of 212123091 in words is "two hundred twelve million, one hundred twenty-three thousand, ninety-one".