21607797 has 4 divisors (see below), whose sum is σ = 28810400. Its totient is φ = 14405196.

The previous prime is 21607771. The next prime is 21607811. The reversal of 21607797 is 79770612.

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.

It is not a de Polignac number, because 21607797 - 2¹⁴ = 21591413 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 (21607757) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3601297 + ... + 3601302.

It is an arithmetic number, because the mean of its divisors is an integer number (7202600).

Almost surely, 2^21607797 is an apocalyptic number.

It is an amenable number.

21607797 is a deficient number, since it is larger than the sum of its proper divisors (7202603).

21607797 is an equidigital number, since it uses as much as digits as its factorization.

21607797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7202602.

The product of its (nonzero) digits is 37044, while the sum is 39.

The square root of 21607797 is about 4648.4187634076. The cubic root of 21607797 is about 278.5288356783.

The spelling of 21607797 in words is "twenty-one million, six hundred seven thousand, seven hundred ninety-seven".