991063554 has 32 divisors (see below), whose sum is σ = 2136744960. Its totient is φ = 304636032.

The previous prime is 991063547. The next prime is 991063559. The reversal of 991063554 is 455360199.

It is a super-2 number, since 2×991063554² = 1964413936134221832, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (991063559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78942 + ... + 90630.

It is an arithmetic number, because the mean of its divisors is an integer number (66773280).

Almost surely, 2^991063554 is an apocalyptic number.

991063554 is an abundant number, since it is smaller than the sum of its proper divisors (1145681406).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

991063554 is a wasteful number, since it uses less digits than its factorization.

991063554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12794.

The product of its (nonzero) digits is 145800, while the sum is 42.

The square root of 991063554 is about 31481.1618908833. The cubic root of 991063554 is about 997.0122670083.

The spelling of 991063554 in words is "nine hundred ninety-one million, sixty-three thousand, five hundred fifty-four".