18961628 has 36 divisors (see below), whose sum is σ = 39070080. Its totient is φ = 8027712.

The previous prime is 18961619. The next prime is 18961643. The reversal of 18961628 is 82616981.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16901 + ... + 17987.

It is an arithmetic number, because the mean of its divisors is an integer number (1085280).

Almost surely, 2^18961628 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18961628, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19535040).

18961628 is an abundant number, since it is smaller than the sum of its proper divisors (20108452).

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

18961628 is a wasteful number, since it uses less digits than its factorization.

18961628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1194 (or 1185 counting only the distinct ones).

The product of its digits is 41472, while the sum is 41.

The square root of 18961628 is about 4354.4951486940. The cubic root of 18961628 is about 266.6604088809.

The spelling of 18961628 in words is "eighteen million, nine hundred sixty-one thousand, six hundred twenty-eight".