21430717 has 8 divisors (see below), whose sum is σ = 26718912. Its totient is φ = 16699200.

The previous prime is 21430697. The next prime is 21430723. The reversal of 21430717 is 71703412.

It is a happy number.

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

It is not a de Polignac number, because 21430717 - 2¹⁵ = 21397949 is a prime.

It is a super-2 number, since 2×21430717² = 918551262268178, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21430691 and 21430700.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21430757) 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, 139084 + ... + 139237.

It is an arithmetic number, because the mean of its divisors is an integer number (3339864).

Almost surely, 2^21430717 is an apocalyptic number.

It is an amenable number.

21430717 is a deficient number, since it is larger than the sum of its proper divisors (5288195).

21430717 is a wasteful number, since it uses less digits than its factorization.

21430717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278339.

The product of its (nonzero) digits is 1176, while the sum is 25.

The square root of 21430717 is about 4629.3322412633. The cubic root of 21430717 is about 277.7658821158.

The spelling of 21430717 in words is "twenty-one million, four hundred thirty thousand, seven hundred seventeen".