20121533 has 2 divisors, whose sum is σ = 20121534. Its totient is φ = 20121532.

The previous prime is 20121467. The next prime is 20121539. The reversal of 20121533 is 33512102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19035769 + 1085764 = 4363^2 + 1042^2 .

It is a cyclic number.

It is not a de Polignac number, because 20121533 - 2¹⁰ = 20120509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20121539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060766 + 10060767.

It is an arithmetic number, because the mean of its divisors is an integer number (10060767).

Almost surely, 2^20121533 is an apocalyptic number.

It is an amenable number.

20121533 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121533 is an equidigital number, since it uses as much as digits as its factorization.

20121533 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 20121533 is about 4485.7031778752. The cubic root of 20121533 is about 271.9904705788.

Adding to 20121533 its reverse (33512102), we get a palindrome (53633635).

The spelling of 20121533 in words is "twenty million, one hundred twenty-one thousand, five hundred thirty-three".