18639770 has 16 divisors (see below), whose sum is σ = 34102728. Its totient is φ = 7333440.

The previous prime is 18639739. The next prime is 18639787. The reversal of 18639770 is 7793681.

It can be written as a sum of positive squares in 4 ways, for example, as 5031049 + 13608721 = 2243^2 + 3689^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14669 + ... + 15888.

Almost surely, 2^18639770 is an apocalyptic number.

18639770 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18639770 is a deficient number, since it is larger than the sum of its proper divisors (15462958).

18639770 is a wasteful number, since it uses less digits than its factorization.

18639770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30625.

The product of its (nonzero) digits is 63504, while the sum is 41.

The square root of 18639770 is about 4317.3799925418. The cubic root of 18639770 is about 265.1430105031.

The spelling of 18639770 in words is "eighteen million, six hundred thirty-nine thousand, seven hundred seventy".