21651146536 has 16 divisors (see below), whose sum is σ = 40618467540. Its totient is φ = 10819555200.

The previous prime is 21651146519. The next prime is 21651146537. The reversal of 21651146536 is 63564115612.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 19239354436 + 2411792100 = 138706^2 + 49110^2 .

It is not an unprimeable number, because it can be changed into a prime (21651146537) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 736951 + ... + 765766.

Almost surely, 2^21651146536 is an apocalyptic number.

It is an amenable number.

21651146536 is a deficient number, since it is larger than the sum of its proper divisors (18967321004).

21651146536 is a wasteful number, since it uses less digits than its factorization.

21651146536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1504524 (or 1504520 counting only the distinct ones).

The product of its digits is 129600, while the sum is 40.

The spelling of 21651146536 in words is "twenty-one billion, six hundred fifty-one million, one hundred forty-six thousand, five hundred thirty-six".