421807 has 2 divisors, whose sum is σ = 421808. Its totient is φ = 421806.

The previous prime is 421801. The next prime is 421831. The reversal of 421807 is 708124.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-421807 is a prime.

It is a super-2 number, since 2×421807² = 355842290498, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210903 + 210904.

It is an arithmetic number, because the mean of its divisors is an integer number (210904).

2⁴²¹⁸⁰⁷ is an apocalyptic number.

421807 is a deficient number, since it is larger than the sum of its proper divisors (1).

421807 is an equidigital number, since it uses as much as digits as its factorization.

421807 is an evil number, because the sum of its binary digits is even.

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

The square root of 421807 is about 649.4667043044. The cubic root of 421807 is about 74.9959701538.

It can be divided in two parts, 42 and 1807, that added together give a square (1849 = 43²).

The spelling of 421807 in words is "four hundred twenty-one thousand, eight hundred seven".