90101821 has 4 divisors (see below), whose sum is σ = 90137152. Its totient is φ = 90066492.

The previous prime is 90101777. The next prime is 90101831. The reversal of 90101821 is 12810109.

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 90101821 - 2¹³ = 90093629 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 90101792 and 90101801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90101831) 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, 13515 + ... + 19048.

It is an arithmetic number, because the mean of its divisors is an integer number (22534288).

Almost surely, 2^90101821 is an apocalyptic number.

It is an amenable number.

90101821 is a deficient number, since it is larger than the sum of its proper divisors (35331).

90101821 is a wasteful number, since it uses less digits than its factorization.

90101821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35330.

The product of its (nonzero) digits is 144, while the sum is 22.

The square root of 90101821 is about 9492.1979014346. The cubic root of 90101821 is about 448.3094113753.

The spelling of 90101821 in words is "ninety million, one hundred one thousand, eight hundred twenty-one".