100455721 has 4 divisors (see below), whose sum is σ = 100673152. Its totient is φ = 100238292.

The previous prime is 100455709. The next prime is 100455767. The reversal of 100455721 is 127554001.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 127554001 = 3259 ⋅39139.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-100455721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (100455791) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 108021 + ... + 108946.

It is an arithmetic number, because the mean of its divisors is an integer number (25168288).

Almost surely, 2^100455721 is an apocalyptic number.

It is an amenable number.

100455721 is a deficient number, since it is larger than the sum of its proper divisors (217431).

100455721 is an equidigital number, since it uses as much as digits as its factorization.

100455721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 217430.

The product of its (nonzero) digits is 1400, while the sum is 25.

The square root of 100455721 is about 10022.7601487814. The cubic root of 100455721 is about 464.8629048189.

The spelling of 100455721 in words is "one hundred million, four hundred fifty-five thousand, seven hundred twenty-one".