770850021721 has 4 divisors (see below), whose sum is σ = 830146177252. Its totient is φ = 711553866192.

The previous prime is 770850021703. The next prime is 770850021731. The reversal of 770850021721 is 127120058077.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 127120058077 = 26171 ⋅4857287.

It can be written as a sum of positive squares in 2 ways, for example, as 146125765696 + 624724256025 = 382264^2 + 790395^2 .

It is not a de Polignac number, because 770850021721 - 2¹³ = 770850013529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (770850021731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29648077746 + ... + 29648077771.

It is an arithmetic number, because the mean of its divisors is an integer number (207536544313).

Almost surely, 2^770850021721 is an apocalyptic number.

It is an amenable number.

770850021721 is a deficient number, since it is larger than the sum of its proper divisors (59296155531).

770850021721 is a wasteful number, since it uses less digits than its factorization.

770850021721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59296155530.

The product of its (nonzero) digits is 54880, while the sum is 40.

Adding to 770850021721 its reverse (127120058077), we get a palindrome (897970079798).

The spelling of 770850021721 in words is "seven hundred seventy billion, eight hundred fifty million, twenty-one thousand, seven hundred twenty-one".