655721011 has 4 divisors (see below), whose sum is σ = 715332024. Its totient is φ = 596110000.

The previous prime is 655720981. The next prime is 655721041. The reversal of 655721011 is 110127556.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (655720981) and next prime (655721041).

It is a cyclic number.

It is not a de Polignac number, because 655721011 - 2⁵ = 655720979 is a prime.

It is not an unprimeable number, because it can be changed into a prime (655721041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29805490 + ... + 29805511.

It is an arithmetic number, because the mean of its divisors is an integer number (178833006).

Almost surely, 2^655721011 is an apocalyptic number.

655721011 is a deficient number, since it is larger than the sum of its proper divisors (59611013).

655721011 is a wasteful number, since it uses less digits than its factorization.

655721011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59611012.

The product of its (nonzero) digits is 2100, while the sum is 28.

The square root of 655721011 is about 25607.0500253348. The cubic root of 655721011 is about 868.7731025997.

Adding to 655721011 its reverse (110127556), we get a palindrome (765848567).

The spelling of 655721011 in words is "six hundred fifty-five million, seven hundred twenty-one thousand, eleven".