42806421 has 32 divisors (see below), whose sum is σ = 72817920. Its totient is φ = 24345792.

The previous prime is 42806417. The next prime is 42806441. The reversal of 42806421 is 12460824.

It is not a de Polignac number, because 42806421 - 2² = 42806417 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42806441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 54991 + ... + 55763.

It is an arithmetic number, because the mean of its divisors is an integer number (2275560).

Almost surely, 2^42806421 is an apocalyptic number.

It is an amenable number.

42806421 is a deficient number, since it is larger than the sum of its proper divisors (30011499).

42806421 is a wasteful number, since it uses less digits than its factorization.

42806421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1082 (or 1076 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 42806421 is about 6542.6616143585. The cubic root of 42806421 is about 349.8132908931.

It can be divided in two parts, 4280 and 6421, that added together give a palindrome (10701).

The spelling of 42806421 in words is "forty-two million, eight hundred six thousand, four hundred twenty-one".