2145969919 has 4 divisors (see below), whose sum is σ = 2203969144. Its totient is φ = 2087970696.

The previous prime is 2145969893. The next prime is 2145969937. The reversal of 2145969919 is 9199695412.

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

It is a cyclic number.

It is not a de Polignac number, because 2145969919 - 2¹⁵ = 2145937151 is a prime.

It is a super-2 number, since 2×2145969919² = 9210373786505733122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2145969919.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2145969949) 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, 28999557 + ... + 28999630.

It is an arithmetic number, because the mean of its divisors is an integer number (550992286).

Almost surely, 2^2145969919 is an apocalyptic number.

2145969919 is a deficient number, since it is larger than the sum of its proper divisors (57999225).

2145969919 is an equidigital number, since it uses as much as digits as its factorization.

2145969919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57999224.

The product of its digits is 1574640, while the sum is 55.

The square root of 2145969919 is about 46324.6146125362. The cubic root of 2145969919 is about 1289.8559458956.

It can be divided in two parts, 21459 and 69919, that added together give a triangular number (91378 = T₄₂₇).

The spelling of 2145969919 in words is "two billion, one hundred forty-five million, nine hundred sixty-nine thousand, nine hundred nineteen".