1221679140 has 48 divisors (see below), whose sum is σ = 3731676480. Its totient is φ = 296164480.

The previous prime is 1221679103. The next prime is 1221679171. The reversal of 1221679140 is 419761221.

It is a happy number.

1221679140 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×1221679140² = 2984999842222279200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

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, 924855 + ... + 926174.

It is an arithmetic number, because the mean of its divisors is an integer number (77743260).

Almost surely, 2^1221679140 is an apocalyptic number.

1221679140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221679140 is an abundant number, since it is smaller than the sum of its proper divisors (2509997340).

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

1221679140 is a wasteful number, since it uses less digits than its factorization.

1221679140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1851052 (or 1851050 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 1221679140 is about 34952.5269472752. The cubic root of 1221679140 is about 1069.0197270039.

It can be divided in two parts, 1221 and 679140, that added together give a triangular number (680361 = T₁₁₆₆).

The spelling of 1221679140 in words is "one billion, two hundred twenty-one million, six hundred seventy-nine thousand, one hundred forty".