21210453777 has 8 divisors (see below), whose sum is σ = 28744221760. Its totient is φ = 13908494160.

The previous prime is 21210453757. The next prime is 21210453799. The reversal of 21210453777 is 77735401212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21210453777 - 2⁶ = 21210453713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21210453707) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57951877 + ... + 57952242.

It is an arithmetic number, because the mean of its divisors is an integer number (3593027720).

Almost surely, 2^21210453777 is an apocalyptic number.

It is an amenable number.

21210453777 is a deficient number, since it is larger than the sum of its proper divisors (7533767983).

21210453777 is a wasteful number, since it uses less digits than its factorization.

21210453777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115904183.

The product of its (nonzero) digits is 82320, while the sum is 39.

Adding to 21210453777 its reverse (77735401212), we get a palindrome (98945854989).

The spelling of 21210453777 in words is "twenty-one billion, two hundred ten million, four hundred fifty-three thousand, seven hundred seventy-seven".