18123021646 has 16 divisors (see below), whose sum is σ = 27601168608. Its totient is φ = 8922944800.

The previous prime is 18123021643. The next prime is 18123021647. The reversal of 18123021646 is 64612032181.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18123021643) 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, 38856 + ... + 194308.

It is an arithmetic number, because the mean of its divisors is an integer number (1725073038).

Almost surely, 2^18123021646 is an apocalyptic number.

18123021646 is a deficient number, since it is larger than the sum of its proper divisors (9478146962).

18123021646 is a wasteful number, since it uses less digits than its factorization.

18123021646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156347.

The product of its (nonzero) digits is 13824, while the sum is 34.

The spelling of 18123021646 in words is "eighteen billion, one hundred twenty-three million, twenty-one thousand, six hundred forty-six".