1556397 has 6 divisors (see below), whose sum is σ = 2248142. Its totient is φ = 1037592.

The previous prime is 1556393. The next prime is 1556413. The reversal of 1556397 is 7936551.

It is a happy number.

1556397 is a `hidden beast` number, since 1 + 5 + 563 + 97 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1320201 + 236196 = 1149^2 + 486^2 .

It is not a de Polignac number, because 1556397 - 2² = 1556393 is a prime.

It is a Duffinian number.

1556397 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1556393) 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, 86458 + ... + 86475.

2^1556397 is an apocalyptic number.

It is an amenable number.

1556397 is a deficient number, since it is larger than the sum of its proper divisors (691745).

1556397 is a wasteful number, since it uses less digits than its factorization.

1556397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172939 (or 172936 counting only the distinct ones).

The product of its digits is 28350, while the sum is 36.

The square root of 1556397 is about 1247.5564115502. The cubic root of 1556397 is about 115.8884430873. Note that the first 3 decimals are identical.

It can be divided in two parts, 1556 and 397, that added together give a triangular number (1953 = T₆₂).

The spelling of 1556397 in words is "one million, five hundred fifty-six thousand, three hundred ninety-seven".