21507604020737 has 2 divisors, whose sum is σ = 21507604020738. Its totient is φ = 21507604020736.

The previous prime is 21507604020649. The next prime is 21507604020779. The reversal of 21507604020737 is 73702040670512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20888272796161 + 619331224576 = 4570369^2 + 786976^2 .

It is a cyclic number.

It is not a de Polignac number, because 21507604020737 - 2³⁰ = 21506530278913 is a prime.

It is not a weakly prime, because it can be changed into another prime (21507604020787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10753802010368 + 10753802010369.

It is an arithmetic number, because the mean of its divisors is an integer number (10753802010369).

Almost surely, 2^{21507604020737} is an apocalyptic number.

It is an amenable number.

21507604020737 is a deficient number, since it is larger than the sum of its proper divisors (1).

21507604020737 is an equidigital number, since it uses as much as digits as its factorization.

21507604020737 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 493920, while the sum is 44.

The spelling of 21507604020737 in words is "twenty-one trillion, five hundred seven billion, six hundred four million, twenty thousand, seven hundred thirty-seven".