21601742 has 4 divisors (see below), whose sum is σ = 32402616. Its totient is φ = 10800870.

The previous prime is 21601721. The next prime is 21601757. The reversal of 21601742 is 24710612.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5400434 + ... + 5400437.

It is an arithmetic number, because the mean of its divisors is an integer number (8100654).

Almost surely, 2^21601742 is an apocalyptic number.

21601742 is a deficient number, since it is larger than the sum of its proper divisors (10800874).

21601742 is a wasteful number, since it uses less digits than its factorization.

21601742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10800873.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 21601742 is about 4647.7674210313. The cubic root of 21601742 is about 278.5028165264.

The spelling of 21601742 in words is "twenty-one million, six hundred one thousand, seven hundred forty-two".