991020003 has 16 divisors (see below), whose sum is σ = 1340590080. Its totient is φ = 651096576.

The previous prime is 991019923. The next prime is 991020007. The reversal of 991020003 is 300020199.

It is a happy number.

It is not a de Polignac number, because 991020003 - 2⁸ = 991019747 is a prime.

It is a super-2 number, since 2×991020003² = 1964241292692240018, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (991020007) 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, 133126 + ... + 140372.

It is an arithmetic number, because the mean of its divisors is an integer number (83786880).

Almost surely, 2^991020003 is an apocalyptic number.

991020003 is a deficient number, since it is larger than the sum of its proper divisors (349570077).

991020003 is a wasteful number, since it uses less digits than its factorization.

991020003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7906.

The product of its (nonzero) digits is 486, while the sum is 24.

The square root of 991020003 is about 31480.4701839093. The cubic root of 991020003 is about 996.9976626582.

The spelling of 991020003 in words is "nine hundred ninety-one million, twenty thousand, three".