63421693513921 has 4 divisors (see below), whose sum is σ = 63495525521200. Its totient is φ = 63347861506644.

The previous prime is 63421693513909. The next prime is 63421693513939. The reversal of 63421693513921 is 12931539612436.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 63421693513921 - 2³¹ = 63419546030273 is a prime.

It is a super-2 number, since 2×63421693513921² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (63421693513961) 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, 36916002351 + ... + 36916004068.

It is an arithmetic number, because the mean of its divisors is an integer number (15873881380300).

Almost surely, 2^{63421693513921} is an apocalyptic number.

It is an amenable number.

63421693513921 is a deficient number, since it is larger than the sum of its proper divisors (73832007279).

63421693513921 is an equidigital number, since it uses as much as digits as its factorization.

63421693513921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73832007278.

The product of its digits is 6298560, while the sum is 55.

The spelling of 63421693513921 in words is "sixty-three trillion, four hundred twenty-one billion, six hundred ninety-three million, five hundred thirteen thousand, nine hundred twenty-one".