1285538100 has 576 divisors, whose sum is σ = 5099673600. Its totient is φ = 241920000.

The previous prime is 1285538077. The next prime is 1285538153. The reversal of 1285538100 is 18355821.

It is a happy number.

It is a super-2 number, since 2×1285538100² = 3305216413103220000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 12728050 + ... + 12728150.

It is an arithmetic number, because the mean of its divisors is an integer number (8853600).

Almost surely, 2^1285538100 is an apocalyptic number.

1285538100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1285538100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2549836800).

1285538100 is an abundant number, since it is smaller than the sum of its proper divisors (3814135500).

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

1285538100 is a wasteful number, since it uses less digits than its factorization.

1285538100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184 (or 177 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 33.

The square root of 1285538100 is about 35854.4014034539. The cubic root of 1285538100 is about 1087.3307016149.

The spelling of 1285538100 in words is "one billion, two hundred eighty-five million, five hundred thirty-eight thousand, one hundred".