21478640184 has 64 divisors (see below), whose sum is σ = 59687258400. Its totient is φ = 7156622592.

The previous prime is 21478640171. The next prime is 21478640203. The reversal of 21478640184 is 48104687412.

It is a super-2 number, since 2×21478640184² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

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 in 15 ways as a sum of consecutive naturals, for example, 546274 + ... + 584270.

Almost surely, 2^21478640184 is an apocalyptic number.

21478640184 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21478640184 is an abundant number, since it is smaller than the sum of its proper divisors (38208618216).

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

21478640184 is a wasteful number, since it uses less digits than its factorization.

21478640184 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40629 (or 40619 counting only the distinct ones).

The product of its (nonzero) digits is 344064, while the sum is 45.

The spelling of 21478640184 in words is "twenty-one billion, four hundred seventy-eight million, six hundred forty thousand, one hundred eighty-four".