9901012021 has 8 divisors (see below), whose sum is σ = 9932229504. Its totient is φ = 9869844000.

The previous prime is 9901011979. The next prime is 9901012027. The reversal of 9901012021 is 1202101099.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 9901012021 - 2⁷ = 9901011893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9901012027) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 411105 + ... + 434521.

It is an arithmetic number, because the mean of its divisors is an integer number (1241528688).

Almost surely, 2^9901012021 is an apocalyptic number.

It is an amenable number.

9901012021 is a deficient number, since it is larger than the sum of its proper divisors (31217483).

9901012021 is a wasteful number, since it uses less digits than its factorization.

9901012021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24731.

The product of its (nonzero) digits is 324, while the sum is 25.

The square root of 9901012021 is about 99503.8291775749. The cubic root of 9901012021 is about 2147.3023328900.

The spelling of 9901012021 in words is "nine billion, nine hundred one million, twelve thousand, twenty-one".