21974429 has 8 divisors (see below), whose sum is σ = 22468608. Its totient is φ = 21485520.

The previous prime is 21974423. The next prime is 21974437. The reversal of 21974429 is 92447912.

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 21974429 - 2⁴ = 21974413 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21974392 and 21974401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21974423) 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, 7799 + ... + 10235.

It is an arithmetic number, because the mean of its divisors is an integer number (2808576).

Almost surely, 2^21974429 is an apocalyptic number.

It is an amenable number.

21974429 is a deficient number, since it is larger than the sum of its proper divisors (494179).

21974429 is a wasteful number, since it uses less digits than its factorization.

21974429 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2635.

The product of its digits is 36288, while the sum is 38.

The square root of 21974429 is about 4687.6890895195. The cubic root of 21974429 is about 280.0953289351.

The spelling of 21974429 in words is "twenty-one million, nine hundred seventy-four thousand, four hundred twenty-nine".