1989323657 has 4 divisors (see below), whose sum is σ = 2016574740. Its totient is φ = 1962072576.

The previous prime is 1989323603. The next prime is 1989323669. The reversal of 1989323657 is 7563239891.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1560171001 + 429152656 = 39499^2 + 20716^2 .

It is a cyclic number.

It is not a de Polignac number, because 1989323657 - 2¹⁴ = 1989307273 is a prime.

It is a super-2 number, since 2×1989323657² = 7914817224599707298, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1989323599 and 1989323608.

It is not an unprimeable number, because it can be changed into a prime (1989323857) 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, 13625432 + ... + 13625577.

It is an arithmetic number, because the mean of its divisors is an integer number (504143685).

Almost surely, 2^1989323657 is an apocalyptic number.

It is an amenable number.

1989323657 is a deficient number, since it is larger than the sum of its proper divisors (27251083).

1989323657 is an equidigital number, since it uses as much as digits as its factorization.

1989323657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27251082.

The product of its digits is 2449440, while the sum is 53.

The square root of 1989323657 is about 44601.8346819949. The cubic root of 1989323657 is about 1257.6751572746.

The spelling of 1989323657 in words is "one billion, nine hundred eighty-nine million, three hundred twenty-three thousand, six hundred fifty-seven".