20121231437 has 2 divisors, whose sum is σ = 20121231438. Its totient is φ = 20121231436.

The previous prime is 20121231409. The next prime is 20121231469. The reversal of 20121231437 is 73413212102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19978691716 + 142539721 = 141346^2 + 11939^2 .

It is a cyclic number.

It is not a de Polignac number, because 20121231437 - 2¹² = 20121227341 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20121231737) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060615718 + 10060615719.

It is an arithmetic number, because the mean of its divisors is an integer number (10060615719).

Almost surely, 2^20121231437 is an apocalyptic number.

It is an amenable number.

20121231437 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121231437 is an equidigital number, since it uses as much as digits as its factorization.

20121231437 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 26.

Adding to 20121231437 its reverse (73413212102), we get a palindrome (93534443539).

The spelling of 20121231437 in words is "twenty billion, one hundred twenty-one million, two hundred thirty-one thousand, four hundred thirty-seven".