521238947 has 2 divisors, whose sum is σ = 521238948. Its totient is φ = 521238946.

The previous prime is 521238937. The next prime is 521238959. The reversal of 521238947 is 749832125.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 521238947 - 2⁸ = 521238691 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a plaindrome in base 12.

It is not a weakly prime, because it can be changed into another prime (521238917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260619473 + 260619474.

It is an arithmetic number, because the mean of its divisors is an integer number (260619474).

Almost surely, 2^521238947 is an apocalyptic number.

521238947 is a deficient number, since it is larger than the sum of its proper divisors (1).

521238947 is an equidigital number, since it uses as much as digits as its factorization.

521238947 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 41.

The square root of 521238947 is about 22830.6580500869. The cubic root of 521238947 is about 804.7832946768.

The spelling of 521238947 in words is "five hundred twenty-one million, two hundred thirty-eight thousand, nine hundred forty-seven".