21720277354 has 4 divisors (see below), whose sum is σ = 32580416034. Its totient is φ = 10860138676.

The previous prime is 21720277331. The next prime is 21720277361. The reversal of 21720277354 is 45377202712.

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

It can be written as a sum of positive squares in only one way, i.e., 21718801129 + 1476225 = 147373^2 + 1215^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5430069337 + ... + 5430069340.

Almost surely, 2^21720277354 is an apocalyptic number.

21720277354 is a deficient number, since it is larger than the sum of its proper divisors (10860138680).

21720277354 is a wasteful number, since it uses less digits than its factorization.

21720277354 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10860138679.

The product of its (nonzero) digits is 164640, while the sum is 40.

The spelling of 21720277354 in words is "twenty-one billion, seven hundred twenty million, two hundred seventy-seven thousand, three hundred fifty-four".