1005661501 has 4 divisors (see below), whose sum is σ = 1083020092. Its totient is φ = 928302912.

The previous prime is 1005661487. The next prime is 1005661523. The reversal of 1005661501 is 1051665001.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 384356025 + 621305476 = 19605^2 + 24926^2 .

It is a cyclic number.

It is not a de Polignac number, because 1005661501 - 2⁷ = 1005661373 is a prime.

It is a super-2 number, since 2×1005661501² = 2022710109187146002, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1005661541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38679276 + ... + 38679301.

It is an arithmetic number, because the mean of its divisors is an integer number (270755023).

Almost surely, 2^1005661501 is an apocalyptic number.

It is an amenable number.

1005661501 is a deficient number, since it is larger than the sum of its proper divisors (77358591).

1005661501 is an equidigital number, since it uses as much as digits as its factorization.

1005661501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77358590.

The product of its (nonzero) digits is 900, while the sum is 25.

The square root of 1005661501 is about 31712.1664507488. The cubic root of 1005661501 is about 1001.8836167602.

The spelling of 1005661501 in words is "one billion, five million, six hundred sixty-one thousand, five hundred one".