2191642406 has 4 divisors (see below), whose sum is σ = 3287463612. Its totient is φ = 1095821202.

The previous prime is 2191642367. The next prime is 2191642421. The reversal of 2191642406 is 6042461912.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 547910600 + ... + 547910603.

It is an arithmetic number, because the mean of its divisors is an integer number (821865903).

Almost surely, 2^2191642406 is an apocalyptic number.

2191642406 is a deficient number, since it is larger than the sum of its proper divisors (1095821206).

2191642406 is a wasteful number, since it uses less digits than its factorization.

2191642406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1095821205.

The product of its (nonzero) digits is 20736, while the sum is 35.

The square root of 2191642406 is about 46814.9805724621. The cubic root of 2191642406 is about 1298.9424152049.

The spelling of 2191642406 in words is "two billion, one hundred ninety-one million, six hundred forty-two thousand, four hundred six".