1001515540 has 24 divisors (see below), whose sum is σ = 2104137000. Its totient is φ = 400424448.

The previous prime is 1001515513. The next prime is 1001515553. The reversal of 1001515540 is 455151001.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 114190596 + 887324944 = 10686^2 + 29788^2 .

It is a super-2 number, since 2×1001515540² = 2006066753722983200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39336 + ... + 59584.

It is an arithmetic number, because the mean of its divisors is an integer number (87672375).

Almost surely, 2^1001515540 is an apocalyptic number.

1001515540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1001515540 is an abundant number, since it is smaller than the sum of its proper divisors (1102621460).

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

1001515540 is a wasteful number, since it uses less digits than its factorization.

1001515540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22731 (or 22729 counting only the distinct ones).

The product of its (nonzero) digits is 500, while the sum is 22.

The square root of 1001515540 is about 31646.7303208404. The cubic root of 1001515540 is about 1000.5049250078.

Adding to 1001515540 its reverse (455151001), we get a palindrome (1456666541).

The spelling of 1001515540 in words is "one billion, one million, five hundred fifteen thousand, five hundred forty".