1028147921 has 2 divisors, whose sum is σ = 1028147922. Its totient is φ = 1028147920.

The previous prime is 1028147899. The next prime is 1028147927. The reversal of 1028147921 is 1297418201.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 804346321 + 223801600 = 28361^2 + 14960^2 .

It is a cyclic number.

It is not a de Polignac number, because 1028147921 - 2¹⁸ = 1027885777 is a prime.

It is not a weakly prime, because it can be changed into another prime (1028147927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 514073960 + 514073961.

It is an arithmetic number, because the mean of its divisors is an integer number (514073961).

Almost surely, 2^1028147921 is an apocalyptic number.

It is an amenable number.

1028147921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1028147921 is an equidigital number, since it uses as much as digits as its factorization.

1028147921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 1028147921 is about 32064.7457654041. The cubic root of 1028147921 is about 1009.2959577336.

The spelling of 1028147921 in words is "one billion, twenty-eight million, one hundred forty-seven thousand, nine hundred twenty-one".