21012376577 has 2 divisors, whose sum is σ = 21012376578. Its totient is φ = 21012376576.

The previous prime is 21012376559. The next prime is 21012376597. The reversal of 21012376577 is 77567321012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19110021121 + 1902355456 = 138239^2 + 43616^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012376577 - 2⁶ = 21012376513 is a prime.

It is not a weakly prime, because it can be changed into another prime (21012376597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506188288 + 10506188289.

It is an arithmetic number, because the mean of its divisors is an integer number (10506188289).

Almost surely, 2^21012376577 is an apocalyptic number.

It is an amenable number.

21012376577 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012376577 is an equidigital number, since it uses as much as digits as its factorization.

21012376577 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 123480, while the sum is 41.

Adding to 21012376577 its reverse (77567321012), we get a palindrome (98579697589).

The spelling of 21012376577 in words is "twenty-one billion, twelve million, three hundred seventy-six thousand, five hundred seventy-seven".