1021240640 has 112 divisors (see below), whose sum is σ = 2797283712. Its totient is φ = 347867136.

The previous prime is 1021240637. The next prime is 1021240651. The reversal of 1021240640 is 460421201.

It is a tau number, because it is divible by the number of its divisors (112).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 363722 + ... + 366518.

Almost surely, 2^1021240640 is an apocalyptic number.

1021240640 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 1021240640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1398641856).

1021240640 is an abundant number, since it is smaller than the sum of its proper divisors (1776043072).

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

1021240640 is a wasteful number, since it uses less digits than its factorization.

1021240640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2984 (or 2974 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 1021240640 is about 31956.8559154370. The cubic root of 1021240640 is about 1007.0306672093.

Adding to 1021240640 its reverse (460421201), we get a palindrome (1481661841).

The spelling of 1021240640 in words is "one billion, twenty-one million, two hundred forty thousand, six hundred forty".