18729690 has 32 divisors (see below), whose sum is σ = 51373440. Its totient is φ = 4281024.

The previous prime is 18729677. The next prime is 18729691. The reversal of 18729690 is 9692781.

It is a super-2 number, since 2×18729690² = 701602574992200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (18729691) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44385 + ... + 44804.

It is an arithmetic number, because the mean of its divisors is an integer number (1605420).

Almost surely, 2^18729690 is an apocalyptic number.

18729690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18729690 is an abundant number, since it is smaller than the sum of its proper divisors (32643750).

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

18729690 is a wasteful number, since it uses less digits than its factorization.

18729690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89206.

The product of its (nonzero) digits is 54432, while the sum is 42.

The square root of 18729690 is about 4327.7811867053. The cubic root of 18729690 is about 265.5686849935.

The spelling of 18729690 in words is "eighteen million, seven hundred twenty-nine thousand, six hundred ninety".