21221523042643 has 8 divisors (see below), whose sum is σ = 26458002754560. Its totient is φ = 16536251721480.

The previous prime is 21221523042617. The next prime is 21221523042661. The reversal of 21221523042643 is 34624032512212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21221523042643 - 2¹³ = 21221523034451 is a prime.

It is a super-3 number, since 3×21221523042643³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21221523042443) 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, 137802097603 + ... + 137802097756.

It is an arithmetic number, because the mean of its divisors is an integer number (3307250344320).

Almost surely, 2^{21221523042643} is an apocalyptic number.

21221523042643 is a deficient number, since it is larger than the sum of its proper divisors (5236479711917).

21221523042643 is a wasteful number, since it uses less digits than its factorization.

21221523042643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 275604195377.

The product of its (nonzero) digits is 138240, while the sum is 37.

Adding to 21221523042643 its reverse (34624032512212), we get a palindrome (55845555554855).

The spelling of 21221523042643 in words is "twenty-one trillion, two hundred twenty-one billion, five hundred twenty-three million, forty-two thousand, six hundred forty-three".