21154647763 has 4 divisors (see below), whose sum is σ = 21168046840. Its totient is φ = 21141248688.

The previous prime is 21154647757. The next prime is 21154647797. The reversal of 21154647763 is 36774645112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21154647763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21154647713) 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, 6697170 + ... + 6700327.

It is an arithmetic number, because the mean of its divisors is an integer number (5292011710).

Almost surely, 2^21154647763 is an apocalyptic number.

21154647763 is a deficient number, since it is larger than the sum of its proper divisors (13399077).

21154647763 is a wasteful number, since it uses less digits than its factorization.

21154647763 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13399076.

The product of its digits is 846720, while the sum is 46.

The spelling of 21154647763 in words is "twenty-one billion, one hundred fifty-four million, six hundred forty-seven thousand, seven hundred sixty-three".