21120021037 has 2 divisors, whose sum is σ = 21120021038. Its totient is φ = 21120021036.

The previous prime is 21120021029. The next prime is 21120021059. The reversal of 21120021037 is 73012002112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21049947396 + 70073641 = 145086^2 + 8371^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120021037 - 2³ = 21120021029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21120021437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560010518 + 10560010519.

It is an arithmetic number, because the mean of its divisors is an integer number (10560010519).

Almost surely, 2^21120021037 is an apocalyptic number.

It is an amenable number.

21120021037 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120021037 is an equidigital number, since it uses as much as digits as its factorization.

21120021037 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 168, while the sum is 19.

Adding to 21120021037 its reverse (73012002112), we get a palindrome (94132023149).

The spelling of 21120021037 in words is "twenty-one billion, one hundred twenty million, twenty-one thousand, thirty-seven".