21140042501 has 2 divisors, whose sum is σ = 21140042502. Its totient is φ = 21140042500.

The previous prime is 21140042491. The next prime is 21140042503. The reversal of 21140042501 is 10524004112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11229640900 + 9910401601 = 105970^2 + 99551^2 .

It is a cyclic number.

It is not a de Polignac number, because 21140042501 - 2³⁰ = 20066300677 is a prime.

Together with 21140042503, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21140042503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10570021250 + 10570021251.

It is an arithmetic number, because the mean of its divisors is an integer number (10570021251).

Almost surely, 2^21140042501 is an apocalyptic number.

It is an amenable number.

21140042501 is a deficient number, since it is larger than the sum of its proper divisors (1).

21140042501 is an equidigital number, since it uses as much as digits as its factorization.

21140042501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 320, while the sum is 20.

Adding to 21140042501 its reverse (10524004112), we get a palindrome (31664046613).

The spelling of 21140042501 in words is "twenty-one billion, one hundred forty million, forty-two thousand, five hundred one".