721533563 has 2 divisors, whose sum is σ = 721533564. Its totient is φ = 721533562.

The previous prime is 721533523. The next prime is 721533577. The reversal of 721533563 is 365335127.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 721533563 - 2²⁶ = 654424699 is a prime.

It is a super-2 number, since 2×721533563² = 1041221365070949938, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (721533523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360766781 + 360766782.

It is an arithmetic number, because the mean of its divisors is an integer number (360766782).

Almost surely, 2^721533563 is an apocalyptic number.

721533563 is a deficient number, since it is larger than the sum of its proper divisors (1).

721533563 is an equidigital number, since it uses as much as digits as its factorization.

721533563 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56700, while the sum is 35.

The square root of 721533563 is about 26861.3767889883. The cubic root of 721533563 is about 896.9168421729.

The spelling of 721533563 in words is "seven hundred twenty-one million, five hundred thirty-three thousand, five hundred sixty-three".