1288891925 has 24 divisors (see below), whose sum is σ = 1611983880. Its totient is φ = 1022284800.

The previous prime is 1288891913. The next prime is 1288891927. The reversal of 1288891925 is 5291988821.

1288891925 = 2235² + 2236² + ... + 2467².

It can be written as a sum of positive squares in 12 ways, for example, as 297838564 + 991053361 = 17258^2 + 31481^2 .

It is not a de Polignac number, because 1288891925 - 2⁶ = 1288891861 is a prime.

It is a super-2 number, since 2×1288891925² = 3322484788660411250, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1288891927) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2382155 + ... + 2382695.

It is an arithmetic number, because the mean of its divisors is an integer number (67165995).

Almost surely, 2^1288891925 is an apocalyptic number.

It is an amenable number.

1288891925 is a deficient number, since it is larger than the sum of its proper divisors (323091955).

1288891925 is a wasteful number, since it uses less digits than its factorization.

1288891925 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1193 (or 1188 counting only the distinct ones).

The product of its digits is 829440, while the sum is 53.

The square root of 1288891925 is about 35901.1409985811. The cubic root of 1288891925 is about 1088.2754552001.

The spelling of 1288891925 in words is "one billion, two hundred eighty-eight million, eight hundred ninety-one thousand, nine hundred twenty-five".