2145355621 has 4 divisors (see below), whose sum is σ = 2146534272. Its totient is φ = 2144176972.

The previous prime is 2145355601. The next prime is 2145355657. The reversal of 2145355621 is 1265535412.

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 2145355621 - 2²³ = 2136967013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2145355601) 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, 586591 + ... + 590236.

It is an arithmetic number, because the mean of its divisors is an integer number (536633568).

Almost surely, 2^2145355621 is an apocalyptic number.

It is an amenable number.

2145355621 is a deficient number, since it is larger than the sum of its proper divisors (1178651).

2145355621 is a wasteful number, since it uses less digits than its factorization.

2145355621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1178650.

The product of its digits is 36000, while the sum is 34.

The square root of 2145355621 is about 46317.9837752033. The cubic root of 2145355621 is about 1289.7328575679.

The spelling of 2145355621 in words is "two billion, one hundred forty-five million, three hundred fifty-five thousand, six hundred twenty-one".