21194647037 has 2 divisors, whose sum is σ = 21194647038. Its totient is φ = 21194647036.

The previous prime is 21194646973. The next prime is 21194647043. The reversal of 21194647037 is 73074649112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16112240356 + 5082406681 = 126934^2 + 71291^2 .

It is a cyclic number.

It is not a de Polignac number, because 21194647037 - 2⁶ = 21194646973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21194647087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10597323518 + 10597323519.

It is an arithmetic number, because the mean of its divisors is an integer number (10597323519).

Almost surely, 2^21194647037 is an apocalyptic number.

It is an amenable number.

21194647037 is a deficient number, since it is larger than the sum of its proper divisors (1).

21194647037 is an equidigital number, since it uses as much as digits as its factorization.

21194647037 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 254016, while the sum is 44.

The spelling of 21194647037 in words is "twenty-one billion, one hundred ninety-four million, six hundred forty-seven thousand, thirty-seven".