1551920 has 40 divisors (see below), whose sum is σ = 3801840. Its totient is φ = 587520.

The previous prime is 1551919. The next prime is 1551929. The reversal of 1551920 is 291551.

It is a tau number, because it is divible by the number of its divisors (40).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1551929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1010 + ... + 2030.

It is an arithmetic number, because the mean of its divisors is an integer number (95046).

2^1551920 is an apocalyptic number.

1551920 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 1551920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1900920).

1551920 is an abundant number, since it is smaller than the sum of its proper divisors (2249920).

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

1551920 is a wasteful number, since it uses less digits than its factorization.

1551920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1053 (or 1047 counting only the distinct ones).

The product of its (nonzero) digits is 450, while the sum is 23.

The square root of 1551920 is about 1245.7608117131. The cubic root of 1551920 is about 115.7772180736. Note that the first 3 decimals are identical.

The spelling of 1551920 in words is "one million, five hundred fifty-one thousand, nine hundred twenty".