101991456 has 72 divisors (see below), whose sum is σ = 331478784. Its totient is φ = 29139840.

The previous prime is 101991401. The next prime is 101991467. The reversal of 101991456 is 654199101.

101991456 is a `hidden beast` number, since 10 + 199 + 1 + 456 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 101991456.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23280 + ... + 27311.

It is an arithmetic number, because the mean of its divisors is an integer number (4603872).

Almost surely, 2^101991456 is an apocalyptic number.

101991456 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

101991456 is an abundant number, since it is smaller than the sum of its proper divisors (229487328).

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

101991456 is a wasteful number, since it uses less digits than its factorization.

101991456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50614 (or 50603 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 36.

The square root of 101991456 is about 10099.0819384734. The cubic root of 101991456 is about 467.2198265965.

The spelling of 101991456 in words is "one hundred one million, nine hundred ninety-one thousand, four hundred fifty-six".