100491621 has 4 divisors (see below), whose sum is σ = 133988832. Its totient is φ = 66994412.

The previous prime is 100491571. The next prime is 100491631. The reversal of 100491621 is 126194001.

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.

It is a cyclic number.

It is not a de Polignac number, because 100491621 - 2⁹ = 100491109 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 100491591 and 100491600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100491631) 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, 16748601 + ... + 16748606.

It is an arithmetic number, because the mean of its divisors is an integer number (33497208).

Almost surely, 2^100491621 is an apocalyptic number.

It is an amenable number.

100491621 is a deficient number, since it is larger than the sum of its proper divisors (33497211).

100491621 is an equidigital number, since it uses as much as digits as its factorization.

100491621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33497210.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 100491621 is about 10024.5509126344. The cubic root of 100491621 is about 464.9182744568.

The spelling of 100491621 in words is "one hundred million, four hundred ninety-one thousand, six hundred twenty-one".