11565671520 has 384 divisors, whose sum is σ = 40242230784. Its totient is φ = 2774974464.

The previous prime is 11565671503. The next prime is 11565671527. The reversal of 11565671520 is 2517656511.

It is a happy number.

It is a super-2 number, since 2×11565671520² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11565671527) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 70954959 + ... + 70955121.

It is an arithmetic number, because the mean of its divisors is an integer number (104797476).

Almost surely, 2^11565671520 is an apocalyptic number.

11565671520 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 11565671520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20121115392).

11565671520 is an abundant number, since it is smaller than the sum of its proper divisors (28676559264).

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

11565671520 is a wasteful number, since it uses less digits than its factorization.

11565671520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414 (or 406 counting only the distinct ones).

The product of its (nonzero) digits is 63000, while the sum is 39.

The spelling of 11565671520 in words is "eleven billion, five hundred sixty-five million, six hundred seventy-one thousand, five hundred twenty".