1645240 has 16 divisors (see below), whose sum is σ = 3701880. Its totient is φ = 658080.

The previous prime is 1645211. The next prime is 1645249. The reversal of 1645240 is 425461.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645249) 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, 20526 + ... + 20605.

2^1645240 is an apocalyptic number.

1645240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1645240 is an abundant number, since it is smaller than the sum of its proper divisors (2056640).

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

1645240 is a wasteful number, since it uses less digits than its factorization.

1645240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41142 (or 41138 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 1645240 is about 1282.6690921668. The cubic root of 1645240 is about 118.0528347137.

The spelling of 1645240 in words is "one million, six hundred forty-five thousand, two hundred forty".