21212737245 has 336 divisors, whose sum is σ = 47973081600. Its totient is φ = 8991404352.

The previous prime is 21212737223. The next prime is 21212737277. The reversal of 21212737245 is 54273721212.

It is not a de Polignac number, because 21212737245 - 2⁶ = 21212737181 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 335 ways as a sum of consecutive naturals, for example, 451334812 + ... + 451334858.

Almost surely, 2^21212737245 is an apocalyptic number.

It is an amenable number.

21212737245 is an abundant number, since it is smaller than the sum of its proper divisors (26760344355).

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

21212737245 is an frugal number, since it uses more digits than its factorization.

21212737245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129 (or 81 counting only the distinct ones).

The product of its digits is 47040, while the sum is 36.

The spelling of 21212737245 in words is "twenty-one billion, two hundred twelve million, seven hundred thirty-seven thousand, two hundred forty-five".