999900551 has 16 divisors (see below), whose sum is σ = 1137884160. Its totient is φ = 871659360.

The previous prime is 999900547. The next prime is 999900569. The reversal of 999900551 is 155009999.

It is not a de Polignac number, because 999900551 - 2² = 999900547 is a prime.

It is a super-2 number, since 2×999900551² = 1999602223780207202, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 999900496 and 999900505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999900511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2456 + ... + 44786.

It is an arithmetic number, because the mean of its divisors is an integer number (71117760).

Almost surely, 2^999900551 is an apocalyptic number.

999900551 is a deficient number, since it is larger than the sum of its proper divisors (137983609).

999900551 is a wasteful number, since it uses less digits than its factorization.

999900551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42446.

The product of its (nonzero) digits is 164025, while the sum is 47.

The square root of 999900551 is about 31621.2041358327. The cubic root of 999900551 is about 999.9668492344.

The spelling of 999900551 in words is "nine hundred ninety-nine million, nine hundred thousand, five hundred fifty-one".