21797029 has 4 divisors (see below), whose sum is σ = 21806784. Its totient is φ = 21787276.

The previous prime is 21797023. The next prime is 21797053. The reversal of 21797029 is 92079712.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21797029 - 2⁹ = 21796517 is a prime.

It is a super-2 number, since 2×21797029² = 950220946453682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21797023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 324 + ... + 6610.

It is an arithmetic number, because the mean of its divisors is an integer number (5451696).

Almost surely, 2^21797029 is an apocalyptic number.

It is an amenable number.

21797029 is a deficient number, since it is larger than the sum of its proper divisors (9755).

21797029 is an equidigital number, since it uses as much as digits as its factorization.

21797029 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9754.

The product of its (nonzero) digits is 15876, while the sum is 37.

The square root of 21797029 is about 4668.7288419869. The cubic root of 21797029 is about 279.3395530969.

The spelling of 21797029 in words is "twenty-one million, seven hundred ninety-seven thousand, twenty-nine".