21012000761 has 2 divisors, whose sum is σ = 21012000762. Its totient is φ = 21012000760.

The previous prime is 21012000749. The next prime is 21012000803. The reversal of 21012000761 is 16700021012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18409062400 + 2602938361 = 135680^2 + 51019^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012000761 - 2²⁶ = 20944891897 is a prime.

It is not a weakly prime, because it can be changed into another prime (21012000701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506000380 + 10506000381.

It is an arithmetic number, because the mean of its divisors is an integer number (10506000381).

Almost surely, 2^21012000761 is an apocalyptic number.

It is an amenable number.

21012000761 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012000761 is an equidigital number, since it uses as much as digits as its factorization.

21012000761 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 168, while the sum is 20.

Adding to 21012000761 its reverse (16700021012), we get a palindrome (37712021773).

The spelling of 21012000761 in words is "twenty-one billion, twelve million, seven hundred sixty-one", and thus it is an aban number.