1989631625 has 16 divisors (see below), whose sum is σ = 2489195280. Its totient is φ = 1587772800.

The previous prime is 1989631613. The next prime is 1989631639. The reversal of 1989631625 is 5261369891.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 606981769 + 1382649856 = 24637^2 + 37184^2 .

It is not a de Polignac number, because 1989631625 - 2⁶ = 1989631561 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31667 + ... + 70583.

It is an arithmetic number, because the mean of its divisors is an integer number (155574705).

Almost surely, 2^1989631625 is an apocalyptic number.

It is an amenable number.

1989631625 is a deficient number, since it is larger than the sum of its proper divisors (499563655).

1989631625 is an equidigital number, since it uses as much as digits as its factorization.

1989631625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39341 (or 39331 counting only the distinct ones).

The product of its digits is 699840, while the sum is 50.

The square root of 1989631625 is about 44605.2869624218. The cubic root of 1989631625 is about 1257.7400543257.

The spelling of 1989631625 in words is "one billion, nine hundred eighty-nine million, six hundred thirty-one thousand, six hundred twenty-five".