1213644651780 has 48 divisors (see below), whose sum is σ = 3707132756544. Its totient is φ = 294216885120.

The previous prime is 1213644651763. The next prime is 1213644651797. The reversal of 1213644651780 is 871564463121.

It is an interprime number because it is at equal distance from previous prime (1213644651763) and next prime (1213644651797).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 919427107 + ... + 919428426.

It is an arithmetic number, because the mean of its divisors is an integer number (77231932428).

Almost surely, 2^{1213644651780} is an apocalyptic number.

1213644651780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1213644651780 is an abundant number, since it is smaller than the sum of its proper divisors (2493488104764).

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

1213644651780 is a wasteful number, since it uses less digits than its factorization.

1213644651780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1838855556 (or 1838855554 counting only the distinct ones).

The product of its (nonzero) digits is 967680, while the sum is 48.

The spelling of 1213644651780 in words is "one trillion, two hundred thirteen billion, six hundred forty-four million, six hundred fifty-one thousand, seven hundred eighty".