1221790 has 16 divisors (see below), whose sum is σ = 2328912. Its totient is φ = 459904.

The previous prime is 1221767. The next prime is 1221791. The reversal of 1221790 is 971221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221791) 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, 3424 + ... + 3763.

It is an arithmetic number, because the mean of its divisors is an integer number (145557).

2^1221790 is an apocalyptic number.

1221790 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221790 is a deficient number, since it is larger than the sum of its proper divisors (1107122).

1221790 is a wasteful number, since it uses less digits than its factorization.

1221790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7211.

The product of its (nonzero) digits is 252, while the sum is 22.

The square root of 1221790 is about 1105.3460996448. The cubic root of 1221790 is about 106.9052061719.

The spelling of 1221790 in words is "one million, two hundred twenty-one thousand, seven hundred ninety".