11891867520 has 384 divisors, whose sum is σ = 41734189440. Its totient is φ = 2878267392.

The previous prime is 11891867483. The next prime is 11891867539. The reversal of 11891867520 is 2576819811.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-2 number, since 2×11891867520² (a number of 21 digits) contains 22 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 11891867520.

It is a congruent number.

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, 21739887 + ... + 21740433.

It is an arithmetic number, because the mean of its divisors is an integer number (108682785).

Almost surely, 2^11891867520 is an apocalyptic number.

11891867520 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 11891867520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20867094720).

11891867520 is an abundant number, since it is smaller than the sum of its proper divisors (29842321920).

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

11891867520 is a wasteful number, since it uses less digits than its factorization.

11891867520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 662 (or 637 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 48.

The spelling of 11891867520 in words is "eleven billion, eight hundred ninety-one million, eight hundred sixty-seven thousand, five hundred twenty".