21223396649 has 32 divisors (see below), whose sum is σ = 27911600640. Its totient is φ = 15659246592.

The previous prime is 21223396639. The next prime is 21223396651. The reversal of 21223396649 is 94669332212.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21223396649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21223396639) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 105692 + ... + 231554.

It is an arithmetic number, because the mean of its divisors is an integer number (872237520).

Almost surely, 2^21223396649 is an apocalyptic number.

It is an amenable number.

21223396649 is a deficient number, since it is larger than the sum of its proper divisors (6688203991).

21223396649 is a wasteful number, since it uses less digits than its factorization.

21223396649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126009.

The product of its digits is 839808, while the sum is 47.

The spelling of 21223396649 in words is "twenty-one billion, two hundred twenty-three million, three hundred ninety-six thousand, six hundred forty-nine".