2145561321 has 8 divisors (see below), whose sum is σ = 2869948224. Its totient is φ = 1425774320.

The previous prime is 2145561287. The next prime is 2145561329. The reversal of 2145561321 is 1231655412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2145561321 - 2⁷ = 2145561193 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2145561329) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1148886 + ... + 1150751.

It is an arithmetic number, because the mean of its divisors is an integer number (358743528).

Almost surely, 2^2145561321 is an apocalyptic number.

It is an amenable number.

2145561321 is a deficient number, since it is larger than the sum of its proper divisors (724386903).

2145561321 is a wasteful number, since it uses less digits than its factorization.

2145561321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2299951.

The product of its digits is 7200, while the sum is 30.

The square root of 2145561321 is about 46320.2042417777. The cubic root of 2145561321 is about 1289.7740767746.

The spelling of 2145561321 in words is "two billion, one hundred forty-five million, five hundred sixty-one thousand, three hundred twenty-one".