421971621 has 8 divisors (see below), whose sum is σ = 565044480. Its totient is φ = 280106592.

The previous prime is 421971619. The next prime is 421971691. The reversal of 421971621 is 126179124.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 421971621 - 2¹ = 421971619 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421971691) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 301141 + ... + 302538.

It is an arithmetic number, because the mean of its divisors is an integer number (70630560).

Almost surely, 2^421971621 is an apocalyptic number.

It is an amenable number.

421971621 is a deficient number, since it is larger than the sum of its proper divisors (143072859).

421971621 is a wasteful number, since it uses less digits than its factorization.

421971621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 603915.

The product of its digits is 6048, while the sum is 33.

The square root of 421971621 is about 20541.9478385084. The cubic root of 421971621 is about 750.0572525183.

The spelling of 421971621 in words is "four hundred twenty-one million, nine hundred seventy-one thousand, six hundred twenty-one".