1220945 has 16 divisors (see below), whose sum is σ = 1624320. Its totient is φ = 873600.

The previous prime is 1220927. The next prime is 1220953. The reversal of 1220945 is 5490221.

It is not a de Polignac number, because 1220945 - 2⁸ = 1220689 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1220945.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4205 + ... + 4485.

It is an arithmetic number, because the mean of its divisors is an integer number (101520).

2^1220945 is an apocalyptic number.

It is an amenable number.

1220945 is a deficient number, since it is larger than the sum of its proper divisors (403375).

1220945 is a wasteful number, since it uses less digits than its factorization.

1220945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 1220945 is about 1104.9638003120. The cubic root of 1220945 is about 106.8805549818.

The spelling of 1220945 in words is "one million, two hundred twenty thousand, nine hundred forty-five".