21366434649 has 64 divisors (see below), whose sum is σ = 34862800896. Its totient is φ = 11362166784.

The previous prime is 21366434587. The next prime is 21366434653. The reversal of 21366434649 is 94643466312.

It is not a de Polignac number, because 21366434649 - 2¹³ = 21366426457 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21366434598 and 21366434607.

It is not an unprimeable number, because it can be changed into a prime (21366434449) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 15014352 + ... + 15015774.

It is an arithmetic number, because the mean of its divisors is an integer number (544731264).

Almost surely, 2^21366434649 is an apocalyptic number.

It is an amenable number.

21366434649 is a deficient number, since it is larger than the sum of its proper divisors (13496366247).

21366434649 is a wasteful number, since it uses less digits than its factorization.

21366434649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1894.

The product of its digits is 2239488, while the sum is 48.

The spelling of 21366434649 in words is "twenty-one billion, three hundred sixty-six million, four hundred thirty-four thousand, six hundred forty-nine".