20546137621 has 2 divisors, whose sum is σ = 20546137622. Its totient is φ = 20546137620.

The previous prime is 20546137607. The next prime is 20546137679. The reversal of 20546137621 is 12673164502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19619604900 + 926532721 = 140070^2 + 30439^2 .

It is a cyclic number.

It is not a de Polignac number, because 20546137621 - 2¹⁵ = 20546104853 is a prime.

It is a super-2 number, since 2×20546137621² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20546137681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10273068810 + 10273068811.

It is an arithmetic number, because the mean of its divisors is an integer number (10273068811).

Almost surely, 2^20546137621 is an apocalyptic number.

It is an amenable number.

20546137621 is a deficient number, since it is larger than the sum of its proper divisors (1).

20546137621 is an equidigital number, since it uses as much as digits as its factorization.

20546137621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60480, while the sum is 37.

The spelling of 20546137621 in words is "twenty billion, five hundred forty-six million, one hundred thirty-seven thousand, six hundred twenty-one".