2155639894 has 4 divisors (see below), whose sum is σ = 3233459844. Its totient is φ = 1077819946.

The previous prime is 2155639891. The next prime is 2155639909. The reversal of 2155639894 is 4989365512.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2155639891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 538909972 + ... + 538909975.

It is an arithmetic number, because the mean of its divisors is an integer number (808364961).

Almost surely, 2^2155639894 is an apocalyptic number.

2155639894 is a deficient number, since it is larger than the sum of its proper divisors (1077819950).

2155639894 is a wasteful number, since it uses less digits than its factorization.

2155639894 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1077819949.

The product of its digits is 2332800, while the sum is 52.

The square root of 2155639894 is about 46428.8691871771. The cubic root of 2155639894 is about 1291.7904537200.

The spelling of 2155639894 in words is "two billion, one hundred fifty-five million, six hundred thirty-nine thousand, eight hundred ninety-four".