228991507 has 2 divisors, whose sum is σ = 228991508. Its totient is φ = 228991506.

The previous prime is 228991493. The next prime is 228991517. The reversal of 228991507 is 705199822.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 228991507 - 2¹¹ = 228989459 is a prime.

It is a super-2 number, since 2×228991507² = 104874220556262098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (228991517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 114495753 + 114495754.

It is an arithmetic number, because the mean of its divisors is an integer number (114495754).

Almost surely, 2^228991507 is an apocalyptic number.

228991507 is a deficient number, since it is larger than the sum of its proper divisors (1).

228991507 is an equidigital number, since it uses as much as digits as its factorization.

228991507 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 43.

The square root of 228991507 is about 15132.4653312010. The cubic root of 228991507 is about 611.7957537850.

The spelling of 228991507 in words is "two hundred twenty-eight million, nine hundred ninety-one thousand, five hundred seven".