2758345721 has 4 divisors (see below), whose sum is σ = 2758491792. Its totient is φ = 2758199652.

The previous prime is 2758345697. The next prime is 2758345853. The reversal of 2758345721 is 1275438572.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2758345721 - 2¹⁴ = 2758329337 is a prime.

It is a super-2 number, since 2×2758345721² = 15216942233118019682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2758345921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39611 + ... + 84176.

It is an arithmetic number, because the mean of its divisors is an integer number (689622948).

Almost surely, 2^2758345721 is an apocalyptic number.

It is an amenable number.

2758345721 is a deficient number, since it is larger than the sum of its proper divisors (146071).

2758345721 is a wasteful number, since it uses less digits than its factorization.

2758345721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146070.

The product of its digits is 470400, while the sum is 44.

The square root of 2758345721 is about 52519.9554550458. The cubic root of 2758345721 is about 1402.4355090807.

The spelling of 2758345721 in words is "two billion, seven hundred fifty-eight million, three hundred forty-five thousand, seven hundred twenty-one".