1864081 has 4 divisors (see below), whose sum is σ = 1945152. Its totient is φ = 1783012.

The previous prime is 1864069. The next prime is 1864087. The reversal of 1864081 is 1804681.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1804681 = 317 ⋅5693.

It is a cyclic number.

It is not a de Polignac number, because 1864081 - 2¹¹ = 1862033 is a prime.

It is a super-2 number, since 2×1864081² = 6949595949122, which contains 22 as substring.

It is a Duffinian number.

1864081 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1864087) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40501 + ... + 40546.

It is an arithmetic number, because the mean of its divisors is an integer number (486288).

2^1864081 is an apocalyptic number.

1864081 is the 864-th centered pentagonal number.

It is an amenable number.

1864081 is a deficient number, since it is larger than the sum of its proper divisors (81071).

1864081 is an equidigital number, since it uses as much as digits as its factorization.

1864081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81070.

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 1864081 is about 1365.3135171088. The cubic root of 1864081 is about 123.0707724991.

It can be divided in two parts, 18640 and 81, that added together give a triangular number (18721 = T₁₉₃).

The spelling of 1864081 in words is "one million, eight hundred sixty-four thousand, eighty-one".