20379661 has 4 divisors (see below), whose sum is σ = 20425500. Its totient is φ = 20333824.

The previous prime is 20379649. The next prime is 20379691. The reversal of 20379661 is 16697302.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16697302 = 2 ⋅8348651.

It can be written as a sum of positive squares in 2 ways, for example, as 13645636 + 6734025 = 3694^2 + 2595^2 .

It is a cyclic number.

It is not a de Polignac number, because 20379661 - 2¹³ = 20371469 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 (20379641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22246 + ... + 23143.

It is an arithmetic number, because the mean of its divisors is an integer number (5106375).

Almost surely, 2^20379661 is an apocalyptic number.

It is an amenable number.

20379661 is a deficient number, since it is larger than the sum of its proper divisors (45839).

20379661 is an equidigital number, since it uses as much as digits as its factorization.

20379661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45838.

The product of its (nonzero) digits is 13608, while the sum is 34.

The square root of 20379661 is about 4514.3837896218. The cubic root of 20379661 is about 273.1486039467.

The spelling of 20379661 in words is "twenty million, three hundred seventy-nine thousand, six hundred sixty-one".