2121407906 has 4 divisors (see below), whose sum is σ = 3182111862. Its totient is φ = 1060703952.

The previous prime is 2121407891. The next prime is 2121407927. The reversal of 2121407906 is 6097041212.

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 only one way, i.e., 1471412881 + 649995025 = 38359^2 + 25495^2 .

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 530351975 + ... + 530351978.

Almost surely, 2^2121407906 is an apocalyptic number.

2121407906 is a deficient number, since it is larger than the sum of its proper divisors (1060703956).

2121407906 is a wasteful number, since it uses less digits than its factorization.

2121407906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1060703955.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 2121407906 is about 46058.7440775365. The cubic root of 2121407906 is about 1284.9159722391.

The spelling of 2121407906 in words is "two billion, one hundred twenty-one million, four hundred seven thousand, nine hundred six".