21201927401 has 2 divisors, whose sum is σ = 21201927402. Its totient is φ = 21201927400.

The previous prime is 21201927379. The next prime is 21201927403. The reversal of 21201927401 is 10472910212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18090519001 + 3111408400 = 134501^2 + 55780^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21201927401 is a prime.

It is a super-2 number, since 2×21201927401² (a number of 21 digits) contains 22 as substring.

Together with 21201927403, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21201927403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600963700 + 10600963701.

It is an arithmetic number, because the mean of its divisors is an integer number (10600963701).

Almost surely, 2^21201927401 is an apocalyptic number.

It is an amenable number.

21201927401 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201927401 is an equidigital number, since it uses as much as digits as its factorization.

21201927401 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 29.

The spelling of 21201927401 in words is "twenty-one billion, two hundred one million, nine hundred twenty-seven thousand, four hundred one".