420187 has 4 divisors (see below), whose sum is σ = 438480. Its totient is φ = 401896.

The previous prime is 420163. The next prime is 420191. The reversal of 420187 is 781024.

420187 = 124² + 125² + ... + 146².

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-420187 is a prime.

It is a super-2 number, since 2×420187² = 353114229938, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (424187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9112 + ... + 9157.

It is an arithmetic number, because the mean of its divisors is an integer number (109620).

2⁴²⁰¹⁸⁷ is an apocalyptic number.

420187 is a deficient number, since it is larger than the sum of its proper divisors (18293).

420187 is a wasteful number, since it uses less digits than its factorization.

420187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18292.

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 420187 is about 648.2183274175. The cubic root of 420187 is about 74.8998366607.

It can be divided in two parts, 42018 and 7, that added together give a square (42025 = 205²).

The spelling of 420187 in words is "four hundred twenty thousand, one hundred eighty-seven".