1285371920 has 160 divisors (see below), whose sum is σ = 3520608000. Its totient is φ = 436230144.

The previous prime is 1285371911. The next prime is 1285371943. The reversal of 1285371920 is 291735821.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3813992 + ... + 3814328.

It is an arithmetic number, because the mean of its divisors is an integer number (22003800).

Almost surely, 2^1285371920 is an apocalyptic number.

1285371920 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 1285371920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1760304000).

1285371920 is an abundant number, since it is smaller than the sum of its proper divisors (2235236080).

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

1285371920 is a wasteful number, since it uses less digits than its factorization.

1285371920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 510 (or 490 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 38.

The square root of 1285371920 is about 35852.0839003816. The cubic root of 1285371920 is about 1087.2838469417.

The spelling of 1285371920 in words is "one billion, two hundred eighty-five million, three hundred seventy-one thousand, nine hundred twenty".