10281920021 has 4 divisors (see below), whose sum is σ = 10335194412. Its totient is φ = 10228645632.

The previous prime is 10281919993. The next prime is 10281920057. The reversal of 10281920021 is 12002918201.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4523235025 + 5758684996 = 67255^2 + 75886^2 .

It is a cyclic number.

It is not a de Polignac number, because 10281920021 - 2²⁶ = 10214811157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10281920221) 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, 26636906 + ... + 26637291.

It is an arithmetic number, because the mean of its divisors is an integer number (2583798603).

Almost surely, 2^10281920021 is an apocalyptic number.

It is an amenable number.

10281920021 is a deficient number, since it is larger than the sum of its proper divisors (53274391).

10281920021 is an equidigital number, since it uses as much as digits as its factorization.

10281920021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53274390.

The product of its (nonzero) digits is 576, while the sum is 26.

The spelling of 10281920021 in words is "ten billion, two hundred eighty-one million, nine hundred twenty thousand, twenty-one".