1005649920 has 408 divisors, whose sum is σ = 3925838592. Its totient is φ = 235929600.

The previous prime is 1005649913. The next prime is 1005649921. The reversal of 1005649920 is 299465001.

1005649920 is a `hidden beast` number, since 1 + 0 + 0 + 5 + 649 + 9 + 2 + 0 = 666.

It is a super-2 number, since 2×1005649920² = 2022663523192012800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1005649921) 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, 32440305 + ... + 32440335.

Almost surely, 2^1005649920 is an apocalyptic number.

1005649920 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 1005649920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1962919296).

1005649920 is an abundant number, since it is smaller than the sum of its proper divisors (2920188672).

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

1005649920 is an equidigital number, since it uses as much as digits as its factorization.

1005649920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85 (or 52 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 1005649920 is about 31711.9838546881. The cubic root of 1005649920 is about 1001.8797709139.

The spelling of 1005649920 in words is "one billion, five million, six hundred forty-nine thousand, nine hundred twenty".