20461649 has 4 divisors (see below), whose sum is σ = 22035636. Its totient is φ = 18887664.

The previous prime is 20461633. The next prime is 20461673. The reversal of 20461649 is 94616402.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6451600 + 14010049 = 2540^2 + 3743^2 .

It is a cyclic number.

It is not a de Polignac number, because 20461649 - 2⁴ = 20461633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20461619) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 786974 + ... + 786999.

It is an arithmetic number, because the mean of its divisors is an integer number (5508909).

Almost surely, 2^20461649 is an apocalyptic number.

It is an amenable number.

20461649 is a deficient number, since it is larger than the sum of its proper divisors (1573987).

20461649 is a wasteful number, since it uses less digits than its factorization.

20461649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1573986.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 20461649 is about 4523.4554269938. The cubic root of 20461649 is about 273.5144089010.

The spelling of 20461649 in words is "twenty million, four hundred sixty-one thousand, six hundred forty-nine".