21601020541 has 2 divisors, whose sum is σ = 21601020542. Its totient is φ = 21601020540.

The previous prime is 21601020499. The next prime is 21601020557. The reversal of 21601020541 is 14502010612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19889460900 + 1711559641 = 141030^2 + 41371^2 .

It is a cyclic number.

It is not a de Polignac number, because 21601020541 - 2¹¹ = 21601018493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21601020041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10800510270 + 10800510271.

It is an arithmetic number, because the mean of its divisors is an integer number (10800510271).

Almost surely, 2^21601020541 is an apocalyptic number.

It is an amenable number.

21601020541 is a deficient number, since it is larger than the sum of its proper divisors (1).

21601020541 is an equidigital number, since it uses as much as digits as its factorization.

21601020541 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 480, while the sum is 22.

The spelling of 21601020541 in words is "twenty-one billion, six hundred one million, twenty thousand, five hundred forty-one".