2158021386 has 32 divisors (see below), whose sum is σ = 4800121920. Its totient is φ = 718662672.

The previous prime is 2158021379. The next prime is 2158021421. The reversal of 2158021386 is 6831208512.

It is a happy number.

2158021386 is a `hidden beast` number, since 21 + 580 + 21 + 38 + 6 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 2158021386.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40741 + ... + 77303.

It is an arithmetic number, because the mean of its divisors is an integer number (150003810).

Almost surely, 2^2158021386 is an apocalyptic number.

2158021386 is an abundant number, since it is smaller than the sum of its proper divisors (2642100534).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2158021386 is a wasteful number, since it uses less digits than its factorization.

2158021386 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37667 (or 37661 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 2158021386 is about 46454.5087800958. The cubic root of 2158021386 is about 1292.2659902310.

Adding to 2158021386 its reverse (6831208512), we get a palindrome (8989229898).

The spelling of 2158021386 in words is "two billion, one hundred fifty-eight million, twenty-one thousand, three hundred eighty-six".