247507021 has 2 divisors, whose sum is σ = 247507022. Its totient is φ = 247507020.

The previous prime is 247507019. The next prime is 247507033. The reversal of 247507021 is 120705742.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 192820996 + 54686025 = 13886^2 + 7395^2 .

It is a cyclic number.

It is not a de Polignac number, because 247507021 - 2¹ = 247507019 is a prime.

It is a super-2 number, since 2×247507021² = 122519450888588882, which contains 22 as substring.

Together with 247507019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (247507061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123753510 + 123753511.

It is an arithmetic number, because the mean of its divisors is an integer number (123753511).

Almost surely, 2^247507021 is an apocalyptic number.

It is an amenable number.

247507021 is a deficient number, since it is larger than the sum of its proper divisors (1).

247507021 is an equidigital number, since it uses as much as digits as its factorization.

247507021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3920, while the sum is 28.

The square root of 247507021 is about 15732.3558629978. The cubic root of 247507021 is about 627.8595546820.

The spelling of 247507021 in words is "two hundred forty-seven million, five hundred seven thousand, twenty-one".