2158214978 has 64 divisors (see below), whose sum is σ = 3637370880. Its totient is φ = 956188800.

The previous prime is 2158214909. The next prime is 2158214999. The reversal of 2158214978 is 8794128512.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6939443 + ... + 6939753.

It is an arithmetic number, because the mean of its divisors is an integer number (56833920).

Almost surely, 2^2158214978 is an apocalyptic number.

2158214978 is a deficient number, since it is larger than the sum of its proper divisors (1479155902).

2158214978 is a wasteful number, since it uses less digits than its factorization.

2158214978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 543.

The product of its digits is 322560, while the sum is 47.

The square root of 2158214978 is about 46456.5924062452. The cubic root of 2158214978 is about 1292.3046313182.

The spelling of 2158214978 in words is "two billion, one hundred fifty-eight million, two hundred fourteen thousand, nine hundred seventy-eight".