2157664494 has 8 divisors (see below), whose sum is σ = 4315329000. Its totient is φ = 719221496.

The previous prime is 2157664493. The next prime is 2157664507. The reversal of 2157664494 is 4944667512.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

2157664494 is an admirable number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2157664493) 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, 179805369 + ... + 179805380.

It is an arithmetic number, because the mean of its divisors is an integer number (539416125).

Almost surely, 2^2157664494 is an apocalyptic number.

2157664494 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

2157664494 is a wasteful number, since it uses less digits than its factorization.

2157664494 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 359610754.

The product of its digits is 1451520, while the sum is 48.

The square root of 2157664494 is about 46450.6673149052. The cubic root of 2157664494 is about 1292.1947483018.

The spelling of 2157664494 in words is "two billion, one hundred fifty-seven million, six hundred sixty-four thousand, four hundred ninety-four".