421243640 has 16 divisors (see below), whose sum is σ = 947798280. Its totient is φ = 168497440.

The previous prime is 421243637. The next prime is 421243649. The reversal of 421243640 is 46342124.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421243649) 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, 5265506 + ... + 5265585.

Almost surely, 2^421243640 is an apocalyptic number.

421243640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

421243640 is an abundant number, since it is smaller than the sum of its proper divisors (526554640).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

421243640 is a wasteful number, since it uses less digits than its factorization.

421243640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10531102 (or 10531098 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 26.

The square root of 421243640 is about 20524.2208134682. The cubic root of 421243640 is about 749.6256739452.

Adding to 421243640 its reverse (46342124), we get a palindrome (467585764).

The spelling of 421243640 in words is "four hundred twenty-one million, two hundred forty-three thousand, six hundred forty".