21701667 has 16 divisors (see below), whose sum is σ = 32802560. Its totient is φ = 12651552.

The previous prime is 21701651. The next prime is 21701683. The reversal of 21701667 is 76610712.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21701651) and next prime (21701683).

It is not a de Polignac number, because 21701667 - 2⁴ = 21701651 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21701467) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13903 + ... + 15384.

It is an arithmetic number, because the mean of its divisors is an integer number (2050160).

Almost surely, 2^21701667 is an apocalyptic number.

21701667 is a deficient number, since it is larger than the sum of its proper divisors (11100893).

21701667 is a wasteful number, since it uses less digits than its factorization.

21701667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29322.

The product of its (nonzero) digits is 3528, while the sum is 30.

The square root of 21701667 is about 4658.5048030457. The cubic root of 21701667 is about 278.9315873936.

The spelling of 21701667 in words is "twenty-one million, seven hundred one thousand, six hundred sixty-seven".