21722061689 has 2 divisors, whose sum is σ = 21722061690. Its totient is φ = 21722061688.

The previous prime is 21722061671. The next prime is 21722061727. The reversal of 21722061689 is 98616022712.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15159765625 + 6562296064 = 123125^2 + 81008^2 .

It is a cyclic number.

It is not a de Polignac number, because 21722061689 - 2³² = 17427094393 is a prime.

It is not a weakly prime, because it can be changed into another prime (21722061629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10861030844 + 10861030845.

It is an arithmetic number, because the mean of its divisors is an integer number (10861030845).

Almost surely, 2^21722061689 is an apocalyptic number.

It is an amenable number.

21722061689 is a deficient number, since it is larger than the sum of its proper divisors (1).

21722061689 is an equidigital number, since it uses as much as digits as its factorization.

21722061689 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145152, while the sum is 44.

The spelling of 21722061689 in words is "twenty-one billion, seven hundred twenty-two million, sixty-one thousand, six hundred eighty-nine".