21357797 has 8 divisors (see below), whose sum is σ = 22752576. Its totient is φ = 19978432.

The previous prime is 21357779. The next prime is 21357803. The reversal of 21357797 is 79775312.

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 21357797 - 2¹⁰ = 21356773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21357397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 923 + ... + 6600.

It is an arithmetic number, because the mean of its divisors is an integer number (2844072).

Almost surely, 2^21357797 is an apocalyptic number.

It is an amenable number.

21357797 is a deficient number, since it is larger than the sum of its proper divisors (1394779).

21357797 is a wasteful number, since it uses less digits than its factorization.

21357797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7707.

The product of its digits is 92610, while the sum is 41.

The square root of 21357797 is about 4621.4496643369. The cubic root of 21357797 is about 277.4504827373.

The spelling of 21357797 in words is "twenty-one million, three hundred fifty-seven thousand, seven hundred ninety-seven".