1311921864 has 192 divisors, whose sum is σ = 3975791040. Its totient is φ = 387502080.

The previous prime is 1311921803. The next prime is 1311921881. The reversal of 1311921864 is 4681291131.

It is a super-2 number, since 2×1311921864² = 3442277954482468992, which contains 22 as substring.

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

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 9576004 + ... + 9576140.

It is an arithmetic number, because the mean of its divisors is an integer number (20707245).

Almost surely, 2^1311921864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1311921864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1987895520).

1311921864 is an abundant number, since it is smaller than the sum of its proper divisors (2663869176).

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

1311921864 is a wasteful number, since it uses less digits than its factorization.

1311921864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 380 (or 373 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 1311921864 is about 36220.4619517753. The cubic root of 1311921864 is about 1094.7190021446.

The spelling of 1311921864 in words is "one billion, three hundred eleven million, nine hundred twenty-one thousand, eight hundred sixty-four".