421421551 has 4 divisors (see below), whose sum is σ = 446211072. Its totient is φ = 396632032.

The previous prime is 421421549. The next prime is 421421573. The reversal of 421421551 is 155124124.

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

It is not a de Polignac number, because 421421551 - 2¹ = 421421549 is a prime.

It is a super-2 number, since 2×421421551² = 355192247294491202, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421421251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12394735 + ... + 12394768.

It is an arithmetic number, because the mean of its divisors is an integer number (111552768).

Almost surely, 2^421421551 is an apocalyptic number.

421421551 is a deficient number, since it is larger than the sum of its proper divisors (24789521).

421421551 is a wasteful number, since it uses less digits than its factorization.

421421551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24789520.

The product of its digits is 1600, while the sum is 25.

The square root of 421421551 is about 20528.5545277791. The cubic root of 421421551 is about 749.7311931502.

Adding to 421421551 its reverse (155124124), we get a palindrome (576545675).

The spelling of 421421551 in words is "four hundred twenty-one million, four hundred twenty-one thousand, five hundred fifty-one".