11951423820 has 216 divisors, whose sum is σ = 42079119264. Its totient is φ = 2689708032.

The previous prime is 11951423819. The next prime is 11951423821. The reversal of 11951423820 is 2832415911.

11951423820 is a `hidden beast` number, since 119 + 514 + 2 + 3 + 8 + 20 = 666.

It is an interprime number because it is at equal distance from previous prime (11951423819) and next prime (11951423821).

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

It is not an unprimeable number, because it can be changed into a prime (11951423821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 5655084 + ... + 5657196.

Almost surely, 2^11951423820 is an apocalyptic number.

11951423820 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 11951423820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21039559632).

11951423820 is an abundant number, since it is smaller than the sum of its proper divisors (30127695444).

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

11951423820 is a wasteful number, since it uses less digits than its factorization.

11951423820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2269 (or 2197 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The spelling of 11951423820 in words is "eleven billion, nine hundred fifty-one million, four hundred twenty-three thousand, eight hundred twenty".