80763387721 has 27 divisors (see below), whose sum is σ = 87366493791. Its totient is φ = 74643945984.

The previous prime is 80763387709. The next prime is 80763387767. The reversal of 80763387721 is 12778336708.

The square root of 80763387721 is 284189.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 13 ways, for example, as 776235321 + 79987152400 = 27861^2 + 282820^2 .

It is not a de Polignac number, because 80763387721 - 2¹⁷ = 80763256649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (80763357721) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 352678435 + ... + 352678663.

Almost surely, 2^80763387721 is an apocalyptic number.

80763387721 is the 284189-th square number.

80763387721 is the 142095-th centered octagonal number.

It is an amenable number.

80763387721 is a deficient number, since it is larger than the sum of its proper divisors (6603106070).

80763387721 is an frugal number, since it uses more digits than its factorization.

80763387721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 638 (or 319 counting only the distinct ones).

The product of its (nonzero) digits is 2370816, while the sum is 52.

The spelling of 80763387721 in words is "eighty billion, seven hundred sixty-three million, three hundred eighty-seven thousand, seven hundred twenty-one".