1219681840 has 80 divisors (see below), whose sum is σ = 3061116576. Its totient is φ = 449280000.

The previous prime is 1219681829. The next prime is 1219681843. The reversal of 1219681840 is 481869121.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 1219681793 and 1219681802.

It is not an unprimeable number, because it can be changed into a prime (1219681843) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 540715 + ... + 542965.

Almost surely, 2^1219681840 is an apocalyptic number.

1219681840 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 1219681840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1530558288).

1219681840 is an abundant number, since it is smaller than the sum of its proper divisors (1841434736).

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

1219681840 is a wasteful number, since it uses less digits than its factorization.

1219681840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2798 (or 2792 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 40.

The square root of 1219681840 is about 34923.9436490211. The cubic root of 1219681840 is about 1068.4368358932.

The spelling of 1219681840 in words is "one billion, two hundred nineteen million, six hundred eighty-one thousand, eight hundred forty".