21577630243 has 4 divisors (see below), whose sum is σ = 23237447968. Its totient is φ = 19917812520.

The previous prime is 21577630229. The next prime is 21577630301. The reversal of 21577630243 is 34203677512.

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

It is a cyclic number.

It is not a de Polignac number, because 21577630243 - 2⁵ = 21577630211 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21577630196 and 21577630205.

It is not an unprimeable number, because it can be changed into a prime (21577630213) 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, 829908843 + ... + 829908868.

It is an arithmetic number, because the mean of its divisors is an integer number (5809361992).

Almost surely, 2^21577630243 is an apocalyptic number.

21577630243 is a deficient number, since it is larger than the sum of its proper divisors (1659817725).

21577630243 is a wasteful number, since it uses less digits than its factorization.

21577630243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1659817724.

The product of its (nonzero) digits is 211680, while the sum is 40.

The spelling of 21577630243 in words is "twenty-one billion, five hundred seventy-seven million, six hundred thirty thousand, two hundred forty-three".