1638478623 has 32 divisors (see below), whose sum is σ = 2444981760. Its totient is φ = 971118720.

The previous prime is 1638478607. The next prime is 1638478651. The reversal of 1638478623 is 3268748361.

1638478623 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1638478623 - 2⁴ = 1638478607 is a prime.

It is a super-2 number, since 2×1638478623² = 5369224396055952258, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1638478663) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 57693 + ... + 81273.

It is an arithmetic number, because the mean of its divisors is an integer number (76405680).

Almost surely, 2^1638478623 is an apocalyptic number.

1638478623 is a deficient number, since it is larger than the sum of its proper divisors (806503137).

1638478623 is a wasteful number, since it uses less digits than its factorization.

1638478623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23679.

The product of its digits is 1161216, while the sum is 48.

The square root of 1638478623 is about 40478.1252406778. The cubic root of 1638478623 is about 1178.9089366597.

The spelling of 1638478623 in words is "one billion, six hundred thirty-eight million, four hundred seventy-eight thousand, six hundred twenty-three".