1556001 has 12 divisors (see below), whose sum is σ = 2275728. Its totient is φ = 1024344.

The previous prime is 1555999. The next prime is 1556003. The reversal of 1556001 is 1006551.

It is an interprime number because it is at equal distance from previous prime (1555999) and next prime (1556003).

It is not a de Polignac number, because 1556001 - 2¹ = 1555999 is a prime.

It is a super-2 number, since 2×1556001² = 4842278224002, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1556003) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 295 + ... + 1788.

It is an arithmetic number, because the mean of its divisors is an integer number (189644).

2^1556001 is an apocalyptic number.

It is an amenable number.

1556001 is a deficient number, since it is larger than the sum of its proper divisors (719727).

1556001 is a wasteful number, since it uses less digits than its factorization.

1556001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2172 (or 2169 counting only the distinct ones).

The product of its (nonzero) digits is 150, while the sum is 18.

The square root of 1556001 is about 1247.3976911956. The cubic root of 1556001 is about 115.8786136080.

The spelling of 1556001 in words is "one million, five hundred fifty-six thousand, one".