1721366563 has 4 divisors (see below), whose sum is σ = 1967276080. Its totient is φ = 1475457048.

The previous prime is 1721366561. The next prime is 1721366599. The reversal of 1721366563 is 3656631271.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3656631271 = 8741 ⋅418331.

It is a cyclic number.

It is not a de Polignac number, because 1721366563 - 2¹ = 1721366561 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1721366561) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122954748 + ... + 122954761.

It is an arithmetic number, because the mean of its divisors is an integer number (491819020).

Almost surely, 2^1721366563 is an apocalyptic number.

1721366563 is a deficient number, since it is larger than the sum of its proper divisors (245909517).

1721366563 is an equidigital number, since it uses as much as digits as its factorization.

1721366563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245909516.

The product of its digits is 136080, while the sum is 40.

The square root of 1721366563 is about 41489.3548154222. The cubic root of 1721366563 is about 1198.4625131290.

The spelling of 1721366563 in words is "one billion, seven hundred twenty-one million, three hundred sixty-six thousand, five hundred sixty-three".