247159021 has 2 divisors, whose sum is σ = 247159022. Its totient is φ = 247159020.

The previous prime is 247158991. The next prime is 247159027. The reversal of 247159021 is 120951742.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 217238121 + 29920900 = 14739^2 + 5470^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-247159021 is a prime.

It is a super-2 number, since 2×247159021² = 122175163323356882, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (247159027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123579510 + 123579511.

It is an arithmetic number, because the mean of its divisors is an integer number (123579511).

Almost surely, 2^247159021 is an apocalyptic number.

It is an amenable number.

247159021 is a deficient number, since it is larger than the sum of its proper divisors (1).

247159021 is an equidigital number, since it uses as much as digits as its factorization.

247159021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 247159021 is about 15721.2919634488. The cubic root of 247159021 is about 627.5651554806.

The spelling of 247159021 in words is "two hundred forty-seven million, one hundred fifty-nine thousand, twenty-one".