11644537872 has 80 divisors (see below), whose sum is σ = 34746829632. Its totient is φ = 3321077760.

The previous prime is 11644537811. The next prime is 11644537873. The reversal of 11644537872 is 27873544611.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (11644537873) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 639673 + ... + 657624.

Almost surely, 2^11644537872 is an apocalyptic number.

11644537872 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

11644537872 is an abundant number, since it is smaller than the sum of its proper divisors (23102291760).

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

11644537872 is a wasteful number, since it uses less digits than its factorization.

11644537872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1297336 (or 1297330 counting only the distinct ones).

The product of its digits is 1128960, while the sum is 48.

The spelling of 11644537872 in words is "eleven billion, six hundred forty-four million, five hundred thirty-seven thousand, eight hundred seventy-two".