1618644 has 12 divisors (see below), whose sum is σ = 3776864. Its totient is φ = 539544.

The previous prime is 1618637. The next prime is 1618663. The reversal of 1618644 is 4468161.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-5 number, since 5×1618644⁵ (a number of 32 digits) contains 55555 as substring.

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, 67432 + ... + 67455.

2^1618644 is an apocalyptic number.

It is an amenable number.

1618644 is an abundant number, since it is smaller than the sum of its proper divisors (2158220).

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

1618644 is a wasteful number, since it uses less digits than its factorization.

1618644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134894 (or 134892 counting only the distinct ones).

The product of its digits is 4608, while the sum is 30.

The square root of 1618644 is about 1272.2594075109. The cubic root of 1618644 is about 117.4132511958.

The spelling of 1618644 in words is "one million, six hundred eighteen thousand, six hundred forty-four".