280121213 has 4 divisors (see below), whose sum is σ = 280619328. Its totient is φ = 279623100.

The previous prime is 280121207. The next prime is 280121243. The reversal of 280121213 is 312121082.

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 280121213 - 2²⁰ = 279072637 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 (280121243) 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, 248213 + ... + 249338.

It is an arithmetic number, because the mean of its divisors is an integer number (70154832).

Almost surely, 2^280121213 is an apocalyptic number.

It is an amenable number.

280121213 is a deficient number, since it is larger than the sum of its proper divisors (498115).

280121213 is an equidigital number, since it uses as much as digits as its factorization.

280121213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 498114.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 280121213 is about 16736.8220699152. The cubic root of 280121213 is about 654.3076521710.

Adding to 280121213 its reverse (312121082), we get a palindrome (592242295).

The spelling of 280121213 in words is "two hundred eighty million, one hundred twenty-one thousand, two hundred thirteen".