1023857640 has 288 divisors, whose sum is σ = 3811724280. Its totient is φ = 236888064.

The previous prime is 1023857633. The next prime is 1023857651. The reversal of 1023857640 is 467583201.

1023857640 is a `hidden beast` number, since 1 + 0 + 2 + 3 + 8 + 5 + 7 + 640 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 219454596 + 804403044 = 14814^2 + 28362^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 1023857595 and 1023857604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1352142 + ... + 1352898.

Almost surely, 2^1023857640 is an apocalyptic number.

1023857640 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 1023857640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1905862140).

1023857640 is an abundant number, since it is smaller than the sum of its proper divisors (2787866640).

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

1023857640 is a wasteful number, since it uses less digits than its factorization.

1023857640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 821 (or 797 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The square root of 1023857640 is about 31997.7755476846. The cubic root of 1023857640 is about 1007.8901288031.

The spelling of 1023857640 in words is "one billion, twenty-three million, eight hundred fifty-seven thousand, six hundred forty".