21154437147 has 4 divisors (see below), whose sum is σ = 28205916200. Its totient is φ = 14102958096.

The previous prime is 21154437133. The next prime is 21154437193. The reversal of 21154437147 is 74173445112.

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

It is not a de Polignac number, because 21154437147 - 2⁷ = 21154437019 is a prime.

It is a super-2 number, since 2×21154437147² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21154437047) 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, 3525739522 + ... + 3525739527.

It is an arithmetic number, because the mean of its divisors is an integer number (7051479050).

Almost surely, 2^21154437147 is an apocalyptic number.

21154437147 is a deficient number, since it is larger than the sum of its proper divisors (7051479053).

21154437147 is an equidigital number, since it uses as much as digits as its factorization.

21154437147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7051479052.

The product of its digits is 94080, while the sum is 39.

The spelling of 21154437147 in words is "twenty-one billion, one hundred fifty-four million, four hundred thirty-seven thousand, one hundred forty-seven".