2121947 has 4 divisors (see below), whose sum is σ = 2126280. Its totient is φ = 2117616.

The previous prime is 2121943. The next prime is 2121967. The reversal of 2121947 is 7491212.

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 2121947 - 2² = 2121943 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2121941) 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, 1322 + ... + 2447.

It is an arithmetic number, because the mean of its divisors is an integer number (531570).

2^2121947 is an apocalyptic number.

2121947 is a deficient number, since it is larger than the sum of its proper divisors (4333).

2121947 is an equidigital number, since it uses as much as digits as its factorization.

2121947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4332.

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

The square root of 2121947 is about 1456.6904269611. The cubic root of 2121947 is about 128.5024804338.

The spelling of 2121947 in words is "two million, one hundred twenty-one thousand, nine hundred forty-seven".