21541423031 has 4 divisors (see below), whose sum is σ = 21547897200. Its totient is φ = 21534948864.

The previous prime is 21541423009. The next prime is 21541423067. The reversal of 21541423031 is 13032414512.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21541423031 - 2⁶ = 21541422967 is a prime.

It is a super-2 number, since 2×21541423031² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21541423931) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3232091 + ... + 3238748.

It is an arithmetic number, because the mean of its divisors is an integer number (5386974300).

Almost surely, 2^21541423031 is an apocalyptic number.

21541423031 is a deficient number, since it is larger than the sum of its proper divisors (6474169).

21541423031 is an equidigital number, since it uses as much as digits as its factorization.

21541423031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6474168.

The product of its (nonzero) digits is 2880, while the sum is 26.

Adding to 21541423031 its reverse (13032414512), we get a palindrome (34573837543).

The spelling of 21541423031 in words is "twenty-one billion, five hundred forty-one million, four hundred twenty-three thousand, thirty-one".