21401622042501 has 4 divisors (see below), whose sum is σ = 28535496056672. Its totient is φ = 14267748028332.

The previous prime is 21401622042469. The next prime is 21401622042523. The reversal of 21401622042501 is 10524022610412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21401622042501 - 2⁵ = 21401622042469 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21401622042551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3566937007081 + ... + 3566937007086.

It is an arithmetic number, because the mean of its divisors is an integer number (7133874014168).

Almost surely, 2^{21401622042501} is an apocalyptic number.

It is an amenable number.

21401622042501 is a deficient number, since it is larger than the sum of its proper divisors (7133874014171).

21401622042501 is an equidigital number, since it uses as much as digits as its factorization.

21401622042501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7133874014170.

The product of its (nonzero) digits is 7680, while the sum is 30.

Adding to 21401622042501 its reverse (10524022610412), we get a palindrome (31925644652913).

The spelling of 21401622042501 in words is "twenty-one trillion, four hundred one billion, six hundred twenty-two million, forty-two thousand, five hundred one".