21251429147 has 4 divisors (see below), whose sum is σ = 22886154480. Its totient is φ = 19616703816.

The previous prime is 21251429141. The next prime is 21251429153. The reversal of 21251429147 is 74192415212.

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

It is an interprime number because it is at equal distance from previous prime (21251429141) and next prime (21251429153).

It is a cyclic number.

It is not a de Polignac number, because 21251429147 - 2¹² = 21251425051 is a prime.

It is a super-2 number, since 2×21251429147² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21251429147.

It is not an unprimeable number, because it can be changed into a prime (21251429141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 817362647 + ... + 817362672.

It is an arithmetic number, because the mean of its divisors is an integer number (5721538620).

Almost surely, 2^21251429147 is an apocalyptic number.

21251429147 is a deficient number, since it is larger than the sum of its proper divisors (1634725333).

21251429147 is a wasteful number, since it uses less digits than its factorization.

21251429147 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1634725332.

The product of its digits is 40320, while the sum is 38.

The spelling of 21251429147 in words is "twenty-one billion, two hundred fifty-one million, four hundred twenty-nine thousand, one hundred forty-seven".