21980229 has 4 divisors (see below), whose sum is σ = 29306976. Its totient is φ = 14653484.

The previous prime is 21980197. The next prime is 21980243. The reversal of 21980229 is 92208912.

It is a happy number.

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 21980229 - 2⁵ = 21980197 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21980229.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21980029) 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, 3663369 + ... + 3663374.

It is an arithmetic number, because the mean of its divisors is an integer number (7326744).

Almost surely, 2^21980229 is an apocalyptic number.

It is an amenable number.

21980229 is a deficient number, since it is larger than the sum of its proper divisors (7326747).

21980229 is an equidigital number, since it uses as much as digits as its factorization.

21980229 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7326746.

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 21980229 is about 4688.3076904145. The cubic root of 21980229 is about 280.1199698484.

The spelling of 21980229 in words is "twenty-one million, nine hundred eighty thousand, two hundred twenty-nine".