21421404362464 has 48 divisors (see below), whose sum is σ = 42592816904400. Its totient is φ = 10604707061760.

The previous prime is 21421404362429. The next prime is 21421404362467. The reversal of 21421404362464 is 46426340412412.

It is a self number, because there is not a number n which added to its sum of digits gives 21421404362464.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21421404362467) 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, 6916039 + ... + 9522310.

It is an arithmetic number, because the mean of its divisors is an integer number (887350352175).

Almost surely, 2^{21421404362464} is an apocalyptic number.

It is an amenable number.

21421404362464 is a deficient number, since it is larger than the sum of its proper divisors (21171412541936).

21421404362464 is a wasteful number, since it uses less digits than its factorization.

21421404362464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16438763 (or 16438755 counting only the distinct ones).

The product of its (nonzero) digits is 884736, while the sum is 43.

Adding to 21421404362464 its reverse (46426340412412), we get a palindrome (67847744774876).

The spelling of 21421404362464 in words is "twenty-one trillion, four hundred twenty-one billion, four hundred four million, three hundred sixty-two thousand, four hundred sixty-four".