21607957 has 8 divisors (see below), whose sum is σ = 24739776. Its totient is φ = 18487392.

The previous prime is 21607933. The next prime is 21607979. The reversal of 21607957 is 75970612.

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

It is not a de Polignac number, because 21607957 - 2⁷ = 21607829 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 (21607657) 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, 1818 + ... + 6820.

It is an arithmetic number, because the mean of its divisors is an integer number (3092472).

Almost surely, 2^21607957 is an apocalyptic number.

It is an amenable number.

21607957 is a deficient number, since it is larger than the sum of its proper divisors (3131819).

21607957 is an equidigital number, since it uses as much as digits as its factorization.

21607957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5627.

The product of its (nonzero) digits is 26460, while the sum is 37.

The square root of 21607957 is about 4648.4359735292. The cubic root of 21607957 is about 278.5295231539.

The spelling of 21607957 in words is "twenty-one million, six hundred seven thousand, nine hundred fifty-seven".