21151415137 has 2 divisors, whose sum is σ = 21151415138. Its totient is φ = 21151415136.

The previous prime is 21151415083. The next prime is 21151415143. The reversal of 21151415137 is 73151415112.

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., 18866670736 + 2284744401 = 137356^2 + 47799^2 .

It is a cyclic number.

It is not a de Polignac number, because 21151415137 - 2⁷ = 21151415009 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21151415099 and 21151415108.

It is not a weakly prime, because it can be changed into another prime (21151415167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10575707568 + 10575707569.

It is an arithmetic number, because the mean of its divisors is an integer number (10575707569).

Almost surely, 2^21151415137 is an apocalyptic number.

It is an amenable number.

21151415137 is a deficient number, since it is larger than the sum of its proper divisors (1).

21151415137 is an equidigital number, since it uses as much as digits as its factorization.

21151415137 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4200, while the sum is 31.

The spelling of 21151415137 in words is "twenty-one billion, one hundred fifty-one million, four hundred fifteen thousand, one hundred thirty-seven".