421664513449 has 9 divisors (see below), whose sum is σ = 435726172701. Its totient is φ = 408042951660.

The previous prime is 421664513441. The next prime is 421664513483. The reversal of 421664513449 is 944315466124.

The square root of 421664513449 is 649357.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 421664513449 - 2³ = 421664513441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (421664513441) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 20119594 + ... + 20140540.

It is an arithmetic number, because the mean of its divisors is an integer number (48414019189).

Almost surely, 2^421664513449 is an apocalyptic number.

421664513449 is the 649357-th square number.

421664513449 is the 324679-th centered octagonal number.

It is an amenable number.

421664513449 is a deficient number, since it is larger than the sum of its proper divisors (14061659252).

421664513449 is an frugal number, since it uses more digits than its factorization.

421664513449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41956 (or 20978 counting only the distinct ones).

The product of its digits is 2488320, while the sum is 49.

Multiplying 421664513449 by its sum of digits (49), we get a square (20661561159001 = 4545499²).

The spelling of 421664513449 in words is "four hundred twenty-one billion, six hundred sixty-four million, five hundred thirteen thousand, four hundred forty-nine".