1251991802880 has 2376 divisors, whose sum is σ = 5815842352632. Its totient is φ = 247329718272.

The previous prime is 1251991802869. The next prime is 1251991802909. The reversal of 1251991802880 is 882081991521.

1251991802880 is a `hidden beast` number, since 12 + 519 + 9 + 18 + 0 + 28 + 80 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 696597221376 + 555394581504 = 834624^2 + 745248^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 6487004064 + ... + 6487004256.

Almost surely, 2^{1251991802880} is an apocalyptic number.

1251991802880 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 1251991802880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2907921176316).

1251991802880 is an abundant number, since it is smaller than the sum of its proper divisors (4563850549752).

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

1251991802880 is a wasteful number, since it uses less digits than its factorization.

1251991802880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281 (or 240 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 54.

The spelling of 1251991802880 in words is "one trillion, two hundred fifty-one billion, nine hundred ninety-one million, eight hundred two thousand, eight hundred eighty".