1000165551 has 24 divisors (see below), whose sum is σ = 1675212672. Its totient is φ = 519565200.

The previous prime is 1000165519. The next prime is 1000165553. The reversal of 1000165551 is 1555610001.

It is not a de Polignac number, because 1000165551 - 2⁵ = 1000165519 is a prime.

It is a super-2 number, since 2×1000165551² = 2000662258814267202, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1000165553) 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, 194265 + ... + 199346.

It is an arithmetic number, because the mean of its divisors is an integer number (69800528).

Almost surely, 2^1000165551 is an apocalyptic number.

1000165551 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1000165551 is a deficient number, since it is larger than the sum of its proper divisors (675047121).

1000165551 is a wasteful number, since it uses less digits than its factorization.

1000165551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393643 (or 393632 counting only the distinct ones).

The product of its (nonzero) digits is 750, while the sum is 24.

The square root of 1000165551 is about 31625.3940845011. The cubic root of 1000165551 is about 1000.0551806217.

Adding to 1000165551 its reverse (1555610001), we get a palindrome (2555775552).

The spelling of 1000165551 in words is "one billion, one hundred sixty-five thousand, five hundred fifty-one".