287131721940 has 576 divisors, whose sum is σ = 1078885785600. Its totient is φ = 63136862208.

The previous prime is 287131721893. The next prime is 287131721951. The reversal of 287131721940 is 49127131782.

287131721940 is a `hidden beast` number, since 2 + 87 + 1 + 317 + 219 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 293890732 + ... + 293891708.

It is an arithmetic number, because the mean of its divisors is an integer number (1873065600).

Almost surely, 2^287131721940 is an apocalyptic number.

287131721940 is a gapful number since it is divisible by the number (20) 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 287131721940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (539442892800).

287131721940 is an abundant number, since it is smaller than the sum of its proper divisors (791754063660).

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

287131721940 is a wasteful number, since it uses less digits than its factorization.

287131721940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1421 (or 1406 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 45.

The spelling of 287131721940 in words is "two hundred eighty-seven billion, one hundred thirty-one million, seven hundred twenty-one thousand, nine hundred forty".