421021331 has 4 divisors (see below), whose sum is σ = 422349792. Its totient is φ = 419692872.

The previous prime is 421021319. The next prime is 421021343. The reversal of 421021331 is 133120124.

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

It is an interprime number because it is at equal distance from previous prime (421021319) and next prime (421021343).

It is a cyclic number.

It is not a de Polignac number, because 421021331 - 2¹⁰ = 421020307 is a prime.

It is a super-2 number, since 2×421021331² = 354517922314023122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (421021351) 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, 663755 + ... + 664388.

It is an arithmetic number, because the mean of its divisors is an integer number (105587448).

Almost surely, 2^421021331 is an apocalyptic number.

421021331 is a deficient number, since it is larger than the sum of its proper divisors (1328461).

421021331 is a wasteful number, since it uses less digits than its factorization.

421021331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1328460.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 421021331 is about 20518.8043267633. The cubic root of 421021331 is about 749.4937804733.

Adding to 421021331 its reverse (133120124), we get a palindrome (554141455).

The spelling of 421021331 in words is "four hundred twenty-one million, twenty-one thousand, three hundred thirty-one".