228492721 has 2 divisors, whose sum is σ = 228492722. Its totient is φ = 228492720.

The previous prime is 228492707. The next prime is 228492749. The reversal of 228492721 is 127294822.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 184416400 + 44076321 = 13580^2 + 6639^2 .

It is a cyclic number.

It is not a de Polignac number, because 228492721 - 2²⁷ = 94274993 is a prime.

It is a super-4 number, since 4×228492721⁴ (a number of 35 digits) contains 4444 as substring.

It is not a weakly prime, because it can be changed into another prime (228492751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 114246360 + 114246361.

It is an arithmetic number, because the mean of its divisors is an integer number (114246361).

Almost surely, 2^228492721 is an apocalyptic number.

It is an amenable number.

228492721 is a deficient number, since it is larger than the sum of its proper divisors (1).

228492721 is an equidigital number, since it uses as much as digits as its factorization.

228492721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32256, while the sum is 37.

The square root of 228492721 is about 15115.9756879932. The cubic root of 228492721 is about 611.3512293121.

The spelling of 228492721 in words is "two hundred twenty-eight million, four hundred ninety-two thousand, seven hundred twenty-one".