1551601728 has 84 divisors (see below), whose sum is σ = 4481553648. Its totient is φ = 513227520.

The previous prime is 1551601721. The next prime is 1551601729. The reversal of 1551601728 is 8271061551.

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

It is a junction number, because it is equal to n+sod(n) for n = 1551601692 and 1551601701.

It is not an unprimeable number, because it can be changed into a prime (1551601721) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 65175 + ... + 85737.

Almost surely, 2^1551601728 is an apocalyptic number.

1551601728 is a gapful number since it is divisible by the number (18) 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 1551601728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2240776824).

1551601728 is an abundant number, since it is smaller than the sum of its proper divisors (2929951920).

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

1551601728 is a wasteful number, since it uses less digits than its factorization.

1551601728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20712 (or 20699 counting only the distinct ones).

The product of its (nonzero) digits is 16800, while the sum is 36.

The square root of 1551601728 is about 39390.3760835055. The cubic root of 1551601728 is about 1157.6930289627.

The spelling of 1551601728 in words is "one billion, five hundred fifty-one million, six hundred one thousand, seven hundred twenty-eight".