21004511137 has 2 divisors, whose sum is σ = 21004511138. Its totient is φ = 21004511136.

The previous prime is 21004511119. The next prime is 21004511197. The reversal of 21004511137 is 73111540012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14426652321 + 6577858816 = 120111^2 + 81104^2 .

It is a cyclic number.

It is not a de Polignac number, because 21004511137 - 2¹¹ = 21004509089 is a prime.

It is not a weakly prime, because it can be changed into another prime (21004511197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10502255568 + 10502255569.

It is an arithmetic number, because the mean of its divisors is an integer number (10502255569).

Almost surely, 2^21004511137 is an apocalyptic number.

It is an amenable number.

21004511137 is a deficient number, since it is larger than the sum of its proper divisors (1).

21004511137 is an equidigital number, since it uses as much as digits as its factorization.

21004511137 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 840, while the sum is 25.

The spelling of 21004511137 in words is "twenty-one billion, four million, five hundred eleven thousand, one hundred thirty-seven".