21649001 has 8 divisors (see below), whose sum is σ = 23714208. Its totient is φ = 19600000.

The previous prime is 21648997. The next prime is 21649031. The reversal of 21649001 is 10094612.

It is a happy number.

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 21649001 - 2² = 21648997 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21649031) 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, 1160 + ... + 6681.

It is an arithmetic number, because the mean of its divisors is an integer number (2964276).

Almost surely, 2^21649001 is an apocalyptic number.

It is an amenable number.

21649001 is a deficient number, since it is larger than the sum of its proper divisors (2065207).

21649001 is a wasteful number, since it uses less digits than its factorization.

21649001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8103.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 21649001 is about 4652.8486973036. The cubic root of 21649001 is about 278.7057658700.

The spelling of 21649001 in words is "twenty-one million, six hundred forty-nine thousand, one".