1638869148 has 72 divisors (see below), whose sum is σ = 4844647808. Its totient is φ = 457355808.

The previous prime is 1638869143. The next prime is 1638869189. The reversal of 1638869148 is 8419688361.

It is a junction number, because it is equal to n+sod(n) for n = 1638869094 and 1638869103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1638869143) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 64786 + ... + 86457.

Almost surely, 2^1638869148 is an apocalyptic number.

1638869148 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1638869148 is an abundant number, since it is smaller than the sum of its proper divisors (3205778660).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1638869148 is a wasteful number, since it uses less digits than its factorization.

1638869148 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151303 (or 151298 counting only the distinct ones).

The product of its digits is 1990656, while the sum is 54.

The square root of 1638869148 is about 40482.9488550427. The cubic root of 1638869148 is about 1179.0025920042.

The spelling of 1638869148 in words is "one billion, six hundred thirty-eight million, eight hundred sixty-nine thousand, one hundred forty-eight".