18139810 has 16 divisors (see below), whose sum is σ = 35163576. Its totient is φ = 6697728.

The previous prime is 18139789. The next prime is 18139811. The reversal of 18139810 is 1893181.

It can be written as a sum of positive squares in 4 ways, for example, as 13564489 + 4575321 = 3683^2 + 2139^2 .

It is a super-2 number, since 2×18139810² = 658105413672200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18139811) 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, 69639 + ... + 69898.

Almost surely, 2^18139810 is an apocalyptic number.

18139810 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18139810 is a deficient number, since it is larger than the sum of its proper divisors (17023766).

18139810 is a wasteful number, since it uses less digits than its factorization.

18139810 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139557.

The product of its (nonzero) digits is 1728, while the sum is 31.

The square root of 18139810 is about 4259.0855826104. The cubic root of 18139810 is about 262.7509195596.

The spelling of 18139810 in words is "eighteen million, one hundred thirty-nine thousand, eight hundred ten".