1221992 has 16 divisors (see below), whose sum is σ = 2315040. Its totient is φ = 604656.

The previous prime is 1221971. The next prime is 1222003. The reversal of 1221992 is 2991221.

It is a happy number.

It is a Smith number, since the sum of its digits (26) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 83 + ... + 1565.

It is an arithmetic number, because the mean of its divisors is an integer number (144690).

2^1221992 is an apocalyptic number.

It is an amenable number.

1221992 is a deficient number, since it is larger than the sum of its proper divisors (1093048).

1221992 is a wasteful number, since it uses less digits than its factorization.

1221992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1592 (or 1588 counting only the distinct ones).

The product of its digits is 648, while the sum is 26.

The square root of 1221992 is about 1105.4374699638. The cubic root of 1221992 is about 106.9110974358.

The spelling of 1221992 in words is "one million, two hundred twenty-one thousand, nine hundred ninety-two".