1251501881540 has 24 divisors (see below), whose sum is σ = 2628773830872. Its totient is φ = 500482680320.

The previous prime is 1251501881503. The next prime is 1251501881557. The reversal of 1251501881540 is 451881051521.

It can be written as a sum of positive squares in 4 ways, for example, as 216692112004 + 1034809769536 = 465502^2 + 1017256^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7292579 + ... + 7462218.

It is an arithmetic number, because the mean of its divisors is an integer number (109532242953).

Almost surely, 2^{1251501881540} is an apocalyptic number.

1251501881540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1251501881540 is an abundant number, since it is smaller than the sum of its proper divisors (1377271949332).

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

1251501881540 is a wasteful number, since it uses less digits than its factorization.

1251501881540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14759047 (or 14759045 counting only the distinct ones).

The product of its (nonzero) digits is 64000, while the sum is 41.

The spelling of 1251501881540 in words is "one trillion, two hundred fifty-one billion, five hundred one million, eight hundred eighty-one thousand, five hundred forty".