764221135421 has 16 divisors (see below), whose sum is σ = 801252203520. Its totient is φ = 728003583360.

The previous prime is 764221135273. The next prime is 764221135423. The reversal of 764221135421 is 124531122467.

It is not a de Polignac number, because 764221135421 - 2¹⁸ = 764220873277 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 (764221135423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 820136 + ... + 1483598.

It is an arithmetic number, because the mean of its divisors is an integer number (50078262720).

Almost surely, 2^764221135421 is an apocalyptic number.

It is an amenable number.

764221135421 is a deficient number, since it is larger than the sum of its proper divisors (37031068099).

764221135421 is a wasteful number, since it uses less digits than its factorization.

764221135421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 664076.

The product of its digits is 80640, while the sum is 38.

Adding to 764221135421 its reverse (124531122467), we get a palindrome (888752257888).

The spelling of 764221135421 in words is "seven hundred sixty-four billion, two hundred twenty-one million, one hundred thirty-five thousand, four hundred twenty-one".