21712061 has 8 divisors (see below), whose sum is σ = 24842880. Its totient is φ = 18588528.

The previous prime is 21712057. The next prime is 21712063. The reversal of 21712061 is 16021712.

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

It is not a de Polignac number, because 21712061 - 2² = 21712057 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 (21712063) 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, 8435 + ... + 10703.

It is an arithmetic number, because the mean of its divisors is an integer number (3105360).

Almost surely, 2^21712061 is an apocalyptic number.

It is an amenable number.

21712061 is a deficient number, since it is larger than the sum of its proper divisors (3130819).

21712061 is a wasteful number, since it uses less digits than its factorization.

21712061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3643.

The product of its (nonzero) digits is 168, while the sum is 20.

The square root of 21712061 is about 4659.6202634979. The cubic root of 21712061 is about 278.9761116566.

Adding to 21712061 its reverse (16021712), we get a palindrome (37733773).

The spelling of 21712061 in words is "twenty-one million, seven hundred twelve thousand, sixty-one".