12921495840 has 480 divisors, whose sum is σ = 50086403136. Its totient is φ = 3124085760.

The previous prime is 12921495833. The next prime is 12921495871. The reversal of 12921495840 is 4859412921.

It is a happy number.

12921495840 is a `hidden beast` number, since 1 + 2 + 9 + 21 + 49 + 584 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (45).

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 79 ways as a sum of consecutive naturals, for example, 34641894 + ... + 34642266.

Almost surely, 2^12921495840 is an apocalyptic number.

12921495840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12921495840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25043201568).

12921495840 is an abundant number, since it is smaller than the sum of its proper divisors (37164907296).

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

12921495840 is an frugal number, since it uses more digits than its factorization.

12921495840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 426 (or 394 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The spelling of 12921495840 in words is "twelve billion, nine hundred twenty-one million, four hundred ninety-five thousand, eight hundred forty".