21401749 has 8 divisors (see below), whose sum is σ = 22194432. Its totient is φ = 20615520.

The previous prime is 21401717. The next prime is 21401761. The reversal of 21401749 is 94710412.

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

It is a cyclic number.

It is not a de Polignac number, because 21401749 - 2⁵ = 21401717 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 (21405749) 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, 5742 + ... + 8704.

It is an arithmetic number, because the mean of its divisors is an integer number (2774304).

Almost surely, 2^21401749 is an apocalyptic number.

It is an amenable number.

21401749 is a deficient number, since it is larger than the sum of its proper divisors (792683).

21401749 is a wasteful number, since it uses less digits than its factorization.

21401749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3227.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 21401749 is about 4626.2024382856. The cubic root of 21401749 is about 277.6406732047.

The spelling of 21401749 in words is "twenty-one million, four hundred one thousand, seven hundred forty-nine".