1578212887 has 4 divisors (see below), whose sum is σ = 1578305440. Its totient is φ = 1578120336.

The previous prime is 1578212863. The next prime is 1578212897. The reversal of 1578212887 is 7882128751.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 7882128751 = 7 ⋅1126018393.

It is a cyclic number.

It is not a de Polignac number, because 1578212887 - 2²³ = 1569824279 is a prime.

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 1578212887.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1578212807) 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, 12462 + ... + 57547.

It is an arithmetic number, because the mean of its divisors is an integer number (394576360).

Almost surely, 2^1578212887 is an apocalyptic number.

1578212887 is a deficient number, since it is larger than the sum of its proper divisors (92553).

1578212887 is an equidigital number, since it uses as much as digits as its factorization.

1578212887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92552.

The product of its digits is 501760, while the sum is 49.

The square root of 1578212887 is about 39726.7276150453. The cubic root of 1578212887 is about 1164.2739892544.

The spelling of 1578212887 in words is "one billion, five hundred seventy-eight million, two hundred twelve thousand, eight hundred eighty-seven".