18949780 has 24 divisors (see below), whose sum is σ = 39876480. Its totient is φ = 7564320.

The previous prime is 18949771. The next prime is 18949787. The reversal of 18949780 is 8794981.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 18949780.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18949787) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17865 + ... + 18895.

It is an arithmetic number, because the mean of its divisors is an integer number (1661520).

Almost surely, 2^18949780 is an apocalyptic number.

18949780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18949780 is an abundant number, since it is smaller than the sum of its proper divisors (20926700).

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

18949780 is a wasteful number, since it uses less digits than its factorization.

18949780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1959 (or 1957 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 46.

The square root of 18949780 is about 4353.1345028611. The cubic root of 18949780 is about 266.6048572023.

The spelling of 18949780 in words is "eighteen million, nine hundred forty-nine thousand, seven hundred eighty".