21651212033 has 8 divisors (see below), whose sum is σ = 23620570176. Its totient is φ = 19682031600.

The previous prime is 21651212029. The next prime is 21651212047. The reversal of 21651212033 is 33021215612.

It is a happy number.

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

It is not a de Polignac number, because 21651212033 - 2² = 21651212029 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21651211993 and 21651212011.

It is not an unprimeable number, because it can be changed into a prime (21651212533) 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, 440660 + ... + 487322.

It is an arithmetic number, because the mean of its divisors is an integer number (2952571272).

Almost surely, 2^21651212033 is an apocalyptic number.

It is an amenable number.

21651212033 is a deficient number, since it is larger than the sum of its proper divisors (1969358143).

21651212033 is a wasteful number, since it uses less digits than its factorization.

21651212033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88855.

The product of its (nonzero) digits is 2160, while the sum is 26.

Adding to 21651212033 its reverse (33021215612), we get a palindrome (54672427645).

The spelling of 21651212033 in words is "twenty-one billion, six hundred fifty-one million, two hundred twelve thousand, thirty-three".