2720781 has 24 divisors (see below), whose sum is σ = 4729920. Its totient is φ = 1472256.

The previous prime is 2720747. The next prime is 2720789. The reversal of 2720781 is 1870272.

It is not a de Polignac number, because 2720781 - 2⁶ = 2720717 is a prime.

It is a super-2 number, since 2×2720781² = 14805298499922, which contains 22 as substring.

2720781 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2720789) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 61 + ... + 2333.

It is an arithmetic number, because the mean of its divisors is an integer number (197080).

2^2720781 is an apocalyptic number.

2720781 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2720781 is a deficient number, since it is larger than the sum of its proper divisors (2009139).

2720781 is a wasteful number, since it uses less digits than its factorization.

2720781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2305 (or 2302 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 27.

The square root of 2720781 is about 1649.4790086570. The cubic root of 2720781 is about 139.6039999894.

The spelling of 2720781 in words is "two million, seven hundred twenty thousand, seven hundred eighty-one".