775533420221 has 4 divisors (see below), whose sum is σ = 886323908832. Its totient is φ = 664742931612.

The previous prime is 775533420217. The next prime is 775533420271. The reversal of 775533420221 is 122024335577.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 775533420221 - 2² = 775533420217 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (775533420271) 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, 55395244295 + ... + 55395244308.

It is an arithmetic number, because the mean of its divisors is an integer number (221580977208).

Almost surely, 2^775533420221 is an apocalyptic number.

It is an amenable number.

775533420221 is a deficient number, since it is larger than the sum of its proper divisors (110790488611).

775533420221 is a wasteful number, since it uses less digits than its factorization.

775533420221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110790488610.

The product of its (nonzero) digits is 352800, while the sum is 41.

Adding to 775533420221 its reverse (122024335577), we get a palindrome (897557755798).

The spelling of 775533420221 in words is "seven hundred seventy-five billion, five hundred thirty-three million, four hundred twenty thousand, two hundred twenty-one".