1551591 has 6 divisors (see below), whose sum is σ = 2241200. Its totient is φ = 1034388.

The previous prime is 1551577. The next prime is 1551593. The reversal of 1551591 is 1951551.

It is not a de Polignac number, because 1551591 - 2⁷ = 1551463 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1551593) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 86191 + ... + 86208.

2^1551591 is an apocalyptic number.

1551591 is a deficient number, since it is larger than the sum of its proper divisors (689609).

1551591 is a wasteful number, since it uses less digits than its factorization.

1551591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172405 (or 172402 counting only the distinct ones).

The product of its digits is 1125, while the sum is 27.

The square root of 1551591 is about 1245.6287568935. The cubic root of 1551591 is about 115.7690360804.

The spelling of 1551591 in words is "one million, five hundred fifty-one thousand, five hundred ninety-one".