1551257809920 has 1408 divisors, whose sum is σ = 6823997107200. Its totient is φ = 325427134464.

The previous prime is 1551257809897. The next prime is 1551257810033. The reversal of 1551257809920 is 299087521551.

1551257809920 is a `hidden beast` number, since 1 + 55 + 12 + 578 + 0 + 9 + 9 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 3987809086 + ... + 3987809474.

Almost surely, 2^{1551257809920} is an apocalyptic number.

1551257809920 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 1551257809920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3411998553600).

1551257809920 is an abundant number, since it is smaller than the sum of its proper divisors (5272739297280).

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

1551257809920 is a wasteful number, since it uses less digits than its factorization.

1551257809920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 760 (or 736 counting only the distinct ones).

The product of its (nonzero) digits is 2268000, while the sum is 54.

The spelling of 1551257809920 in words is "one trillion, five hundred fifty-one billion, two hundred fifty-seven million, eight hundred nine thousand, nine hundred twenty".