1551661056 has 192 divisors, whose sum is σ = 5016211200. Its totient is φ = 470016000.

The previous prime is 1551661039. The next prime is 1551661091. The reversal of 1551661056 is 6501661551.

It is a tau number, because it is divible by the number of its divisors (192).

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

It is a self number, because there is not a number n which added to its sum of digits gives 1551661056.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 606981 + ... + 609531.

It is an arithmetic number, because the mean of its divisors is an integer number (26126100).

Almost surely, 2^1551661056 is an apocalyptic number.

1551661056 is a gapful number since it is divisible by the number (16) 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 1551661056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2508105600).

1551661056 is an abundant number, since it is smaller than the sum of its proper divisors (3464550144).

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

1551661056 is a wasteful number, since it uses less digits than its factorization.

1551661056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2593 (or 2567 counting only the distinct ones).

The product of its (nonzero) digits is 27000, while the sum is 36.

The square root of 1551661056 is about 39391.1291536559. The cubic root of 1551661056 is about 1157.7077841960.

The spelling of 1551661056 in words is "one billion, five hundred fifty-one million, six hundred sixty-one thousand, fifty-six".