21151420167 has 4 divisors (see below), whose sum is σ = 28201893560. Its totient is φ = 14100946776.

The previous prime is 21151420159. The next prime is 21151420231. The reversal of 21151420167 is 76102415112.

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

It is not a de Polignac number, because 21151420167 - 2³ = 21151420159 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 (21151420127) 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, 3525236692 + ... + 3525236697.

It is an arithmetic number, because the mean of its divisors is an integer number (7050473390).

Almost surely, 2^21151420167 is an apocalyptic number.

21151420167 is a deficient number, since it is larger than the sum of its proper divisors (7050473393).

21151420167 is an equidigital number, since it uses as much as digits as its factorization.

21151420167 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7050473392.

The product of its (nonzero) digits is 3360, while the sum is 30.

Adding to 21151420167 its reverse (76102415112), we get a palindrome (97253835279).

The spelling of 21151420167 in words is "twenty-one billion, one hundred fifty-one million, four hundred twenty thousand, one hundred sixty-seven".