20156618 has 4 divisors (see below), whose sum is σ = 30234930. Its totient is φ = 10078308.

The previous prime is 20156599. The next prime is 20156621. The reversal of 20156618 is 81665102.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 12411529 + 7745089 = 3523^2 + 2783^2 .

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 as a sum of consecutive naturals, namely, 5039153 + ... + 5039156.

Almost surely, 2^20156618 is an apocalyptic number.

20156618 is a deficient number, since it is larger than the sum of its proper divisors (10078312).

20156618 is a wasteful number, since it uses less digits than its factorization.

20156618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10078311.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 20156618 is about 4489.6122326989. The cubic root of 20156618 is about 272.1484645810.

The spelling of 20156618 in words is "twenty million, one hundred fifty-six thousand, six hundred eighteen".