2720769921 has 9 divisors (see below), whose sum is σ = 3930227041. Its totient is φ = 1813742292.

The previous prime is 2720769899. The next prime is 2720769929. The reversal of 2720769921 is 1299670272.

The square root of 2720769921 is 52161.

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

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 2720769921 - 2⁹ = 2720769409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2720769929) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 147790 + ... + 165176.

Almost surely, 2^2720769921 is an apocalyptic number.

2720769921 is the 52161-st square number.

2720769921 is the 26081-st centered octagonal number.

It is an amenable number.

2720769921 is a deficient number, since it is larger than the sum of its proper divisors (1209457120).

2720769921 is an frugal number, since it uses more digits than its factorization.

2720769921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34780 (or 17390 counting only the distinct ones).

The product of its (nonzero) digits is 190512, while the sum is 45.

The cubic root of 2720769921 is about 1396.0381050031.

It can be divided in two parts, 2720 and 769921, that added together give a square (772641 = 879²).

The spelling of 2720769921 in words is "two billion, seven hundred twenty million, seven hundred sixty-nine thousand, nine hundred twenty-one".