1221793679 has 4 divisors (see below), whose sum is σ = 1222882776. Its totient is φ = 1220704584.

The previous prime is 1221793673. The next prime is 1221793711. The reversal of 1221793679 is 9763971221.

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 1221793679 - 2⁴ = 1221793663 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221793673) 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, 542864 + ... + 545109.

It is an arithmetic number, because the mean of its divisors is an integer number (305720694).

Almost surely, 2^1221793679 is an apocalyptic number.

1221793679 is a deficient number, since it is larger than the sum of its proper divisors (1089097).

1221793679 is a wasteful number, since it uses less digits than its factorization.

1221793679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1089096.

The product of its digits is 285768, while the sum is 47.

The square root of 1221793679 is about 34954.1654027099. The cubic root of 1221793679 is about 1069.0531347457.

The spelling of 1221793679 in words is "one billion, two hundred twenty-one million, seven hundred ninety-three thousand, six hundred seventy-nine".