2151452517721 has 4 divisors (see below), whose sum is σ = 2316948865252. Its totient is φ = 1985956170192.

The previous prime is 2151452517673. The next prime is 2151452517793. The reversal of 2151452517721 is 1277152541512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 636987553225 + 1514464964496 = 798115^2 + 1230636^2 .

It is a cyclic number.

It is not a de Polignac number, because 2151452517721 - 2⁷ = 2151452517593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2151452517121) 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, 82748173746 + ... + 82748173771.

It is an arithmetic number, because the mean of its divisors is an integer number (579237216313).

Almost surely, 2^{2151452517721} is an apocalyptic number.

It is an amenable number.

2151452517721 is a deficient number, since it is larger than the sum of its proper divisors (165496347531).

2151452517721 is a wasteful number, since it uses less digits than its factorization.

2151452517721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165496347530.

The product of its digits is 196000, while the sum is 43.

The spelling of 2151452517721 in words is "two trillion, one hundred fifty-one billion, four hundred fifty-two million, five hundred seventeen thousand, seven hundred twenty-one".