1131681780 has 120 divisors (see below), whose sum is σ = 3600495360. Its totient is φ = 297501120.

The previous prime is 1131681769. The next prime is 1131681799. The reversal of 1131681780 is 871861311.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 110101 + ... + 119939.

It is an arithmetic number, because the mean of its divisors is an integer number (30004128).

Almost surely, 2^1131681780 is an apocalyptic number.

1131681780 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 1131681780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1800247680).

1131681780 is an abundant number, since it is smaller than the sum of its proper divisors (2468813580).

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

1131681780 is a wasteful number, since it uses less digits than its factorization.

1131681780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9931 (or 9920 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The square root of 1131681780 is about 33640.4782962431. The cubic root of 1131681780 is about 1042.0969095314.

It can be divided in two parts, 11316 and 81780, that added together give a triangular number (93096 = T₄₃₁).

The spelling of 1131681780 in words is "one billion, one hundred thirty-one million, six hundred eighty-one thousand, seven hundred eighty".