2157187654 has 4 divisors (see below), whose sum is σ = 3235781484. Its totient is φ = 1078593826.

The previous prime is 2157187639. The next prime is 2157187657. The reversal of 2157187654 is 4567817512.

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 (2157187657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 539296912 + ... + 539296915.

It is an arithmetic number, because the mean of its divisors is an integer number (808945371).

Almost surely, 2^2157187654 is an apocalyptic number.

2157187654 is a deficient number, since it is larger than the sum of its proper divisors (1078593830).

2157187654 is a wasteful number, since it uses less digits than its factorization.

2157187654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1078593829.

The product of its digits is 470400, while the sum is 46.

The square root of 2157187654 is about 46445.5342740290. The cubic root of 2157187654 is about 1292.0995503780.

The spelling of 2157187654 in words is "two billion, one hundred fifty-seven million, one hundred eighty-seven thousand, six hundred fifty-four".