1989778925 has 12 divisors (see below), whose sum is σ = 2498560320. Its totient is φ = 1571671920.

The previous prime is 1989778883. The next prime is 1989778937. The reversal of 1989778925 is 5298779891.

It is not a de Polignac number, because 1989778925 - 2¹⁰ = 1989777901 is a prime.

It is a super-3 number, since 3×1989778925³ (a number of 29 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 501767 + ... + 505716.

It is an arithmetic number, because the mean of its divisors is an integer number (208213360).

Almost surely, 2^1989778925 is an apocalyptic number.

It is an amenable number.

1989778925 is a deficient number, since it is larger than the sum of its proper divisors (508781395).

1989778925 is a wasteful number, since it uses less digits than its factorization.

1989778925 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1007572 (or 1007567 counting only the distinct ones).

The product of its digits is 22861440, while the sum is 65.

The square root of 1989778925 is about 44606.9380814241. The cubic root of 1989778925 is about 1257.7710919871.

The spelling of 1989778925 in words is "one billion, nine hundred eighty-nine million, seven hundred seventy-eight thousand, nine hundred twenty-five".