421637641 has 4 divisors (see below), whose sum is σ = 436176900. Its totient is φ = 407098384.

The previous prime is 421637609. The next prime is 421637651. The reversal of 421637641 is 146736124.

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

It can be written as a sum of positive squares in 2 ways, for example, as 165765625 + 255872016 = 12875^2 + 15996^2 .

It is a cyclic number.

It is not a de Polignac number, because 421637641 - 2⁵ = 421637609 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 421637597 and 421637606.

It is not an unprimeable number, because it can be changed into a prime (421637651) 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, 7269586 + ... + 7269643.

It is an arithmetic number, because the mean of its divisors is an integer number (109044225).

Almost surely, 2^421637641 is an apocalyptic number.

It is an amenable number.

421637641 is a deficient number, since it is larger than the sum of its proper divisors (14539259).

421637641 is a wasteful number, since it uses less digits than its factorization.

421637641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14539258.

The product of its digits is 24192, while the sum is 34.

The square root of 421637641 is about 20533.8170099960. The cubic root of 421637641 is about 749.8593164273.

The spelling of 421637641 in words is "four hundred twenty-one million, six hundred thirty-seven thousand, six hundred forty-one".