101011021721 has 2 divisors, whose sum is σ = 101011021722. Its totient is φ = 101011021720.

The previous prime is 101011021717. The next prime is 101011021751. The reversal of 101011021721 is 127120110101.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 95706084496 + 5304937225 = 309364^2 + 72835^2 .

It is a cyclic number.

It is not a de Polignac number, because 101011021721 - 2² = 101011021717 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 101011021721.

It is not a weakly prime, because it can be changed into another prime (101011021751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50505510860 + 50505510861.

It is an arithmetic number, because the mean of its divisors is an integer number (50505510861).

Almost surely, 2^101011021721 is an apocalyptic number.

It is an amenable number.

101011021721 is a deficient number, since it is larger than the sum of its proper divisors (1).

101011021721 is an equidigital number, since it uses as much as digits as its factorization.

101011021721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28, while the sum is 17.

Adding to 101011021721 its reverse (127120110101), we get a palindrome (228131131822).

The spelling of 101011021721 in words is "one hundred one billion, eleven million, twenty-one thousand, seven hundred twenty-one".