21213554606400 has 168 divisors, whose sum is σ = 74951840143264. Its totient is φ = 5221798041600.

The previous prime is 21213554606393. The next prime is 21213554606407. The reversal of 21213554606400 is 460645531212.

It is an interprime number because it is at equal distance from previous prime (21213554606393) and next prime (21213554606407).

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213554606407) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 169918006 + ... + 170042805.

Almost surely, 2^{21213554606400} is an apocalyptic number.

21213554606400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21213554606400 is an abundant number, since it is smaller than the sum of its proper divisors (53738285536864).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21213554606400 is a wasteful number, since it uses less digits than its factorization.

21213554606400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 339960849 (or 339960834 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 39.

The spelling of 21213554606400 in words is "twenty-one trillion, two hundred thirteen billion, five hundred fifty-four million, six hundred six thousand, four hundred".