1222638891 has 8 divisors (see below), whose sum is σ = 1639192464. Its totient is φ = 810588960.

The previous prime is 1222638881. The next prime is 1222638917. The reversal of 1222638891 is 1988362221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1222638891 - 2⁹ = 1222638379 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1222638881) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1125276 + ... + 1126361.

It is an arithmetic number, because the mean of its divisors is an integer number (204899058).

Almost surely, 2^1222638891 is an apocalyptic number.

1222638891 is a deficient number, since it is larger than the sum of its proper divisors (416553573).

1222638891 is a wasteful number, since it uses less digits than its factorization.

1222638891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2251821.

The product of its digits is 82944, while the sum is 42.

The square root of 1222638891 is about 34966.2536025809. The cubic root of 1222638891 is about 1069.2995943226.

The spelling of 1222638891 in words is "one billion, two hundred twenty-two million, six hundred thirty-eight thousand, eight hundred ninety-one".