20078761 has 4 divisors (see below), whose sum is σ = 20378512. Its totient is φ = 19779012.

The previous prime is 20078749. The next prime is 20078771. The reversal of 20078761 is 16787002.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20078761 - 2⁷ = 20078633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20078741) 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, 149775 + ... + 149908.

It is an arithmetic number, because the mean of its divisors is an integer number (5094628).

Almost surely, 2^20078761 is an apocalyptic number.

It is an amenable number.

20078761 is a deficient number, since it is larger than the sum of its proper divisors (299751).

20078761 is an equidigital number, since it uses as much as digits as its factorization.

20078761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299750.

The product of its (nonzero) digits is 4704, while the sum is 31.

The square root of 20078761 is about 4480.9330501582. The cubic root of 20078761 is about 271.7976120251.

It can be divided in two parts, 200 and 78761, that added together give a square (78961 = 281²).

The spelling of 20078761 in words is "twenty million, seventy-eight thousand, seven hundred sixty-one".