1551864 has 16 divisors (see below), whose sum is σ = 3879720. Its totient is φ = 517280.

The previous prime is 1551859. The next prime is 1551871. The reversal of 1551864 is 4681551.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32307 + ... + 32354.

2^1551864 is an apocalyptic number.

It is an amenable number.

1551864 is an abundant number, since it is smaller than the sum of its proper divisors (2327856).

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

1551864 is a wasteful number, since it uses less digits than its factorization.

1551864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64670 (or 64666 counting only the distinct ones).

The product of its digits is 4800, while the sum is 30.

The square root of 1551864 is about 1245.7383352855. The cubic root of 1551864 is about 115.7758254756.

It can be divided in two parts, 1551 and 864, that added together give a triangular number (2415 = T₆₉).

The spelling of 1551864 in words is "one million, five hundred fifty-one thousand, eight hundred sixty-four".