90999945 has 24 divisors (see below), whose sum is σ = 158985216. Its totient is φ = 48148128.

The previous prime is 90999899. The next prime is 90999947. The reversal of 90999945 is 54999909.

It is a happy number.

It is not a de Polignac number, because 90999945 - 2⁷ = 90999817 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 90999891 and 90999900.

It is not an unprimeable number, because it can be changed into a prime (90999947) 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, 2247 + ... + 13676.

It is an arithmetic number, because the mean of its divisors is an integer number (6624384).

Almost surely, 2^90999945 is an apocalyptic number.

It is an amenable number.

90999945 is a deficient number, since it is larger than the sum of its proper divisors (67985271).

90999945 is a wasteful number, since it uses less digits than its factorization.

90999945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16061 (or 16058 counting only the distinct ones).

The product of its (nonzero) digits is 1180980, while the sum is 54.

The square root of 90999945 is about 9539.3891313857. The cubic root of 90999945 is about 449.7940539097.

It can be divided in two parts, 9099 and 9945, that added together give a square (19044 = 138²).

The spelling of 90999945 in words is "ninety million, nine hundred ninety-nine thousand, nine hundred forty-five".