21475129 has 8 divisors (see below), whose sum is σ = 23163392. Its totient is φ = 19792080.

The previous prime is 21475127. The next prime is 21475147. The reversal of 21475129 is 92157412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21475129 - 2¹ = 21475127 is a prime.

It is a super-2 number, since 2×21475129² = 922362331133282, which 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 21475129.

It is not an unprimeable number, because it can be changed into a prime (21475127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13864 + ... + 15334.

It is an arithmetic number, because the mean of its divisors is an integer number (2895424).

Almost surely, 2^21475129 is an apocalyptic number.

It is an amenable number.

21475129 is a deficient number, since it is larger than the sum of its proper divisors (1688263).

21475129 is a wasteful number, since it uses less digits than its factorization.

21475129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2607.

The product of its digits is 5040, while the sum is 31.

The square root of 21475129 is about 4634.1265627948. The cubic root of 21475129 is about 277.9576259967.

The spelling of 21475129 in words is "twenty-one million, four hundred seventy-five thousand, one hundred twenty-nine".