1228720 has 20 divisors (see below), whose sum is σ = 2856960. Its totient is φ = 491456.

The previous prime is 1228693. The next prime is 1228741. The reversal of 1228720 is 278221.

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 1228691 and 1228700.

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, 7600 + ... + 7759.

It is an arithmetic number, because the mean of its divisors is an integer number (142848).

2^1228720 is an apocalyptic number.

1228720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1228720 is an abundant number, since it is smaller than the sum of its proper divisors (1628240).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1228720 is a wasteful number, since it uses less digits than its factorization.

1228720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15372 (or 15366 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 1228720 is about 1108.4764318649. The cubic root of 1228720 is about 107.1069475427.

The spelling of 1228720 in words is "one million, two hundred twenty-eight thousand, seven hundred twenty".