21770077 has 4 divisors (see below), whose sum is σ = 24880096. Its totient is φ = 18660060.

The previous prime is 21770059. The next prime is 21770087. The reversal of 21770077 is 77007712.

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 21770077 - 2¹¹ = 21768029 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 (21770017) 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, 1554999 + ... + 1555012.

It is an arithmetic number, because the mean of its divisors is an integer number (6220024).

Almost surely, 2^21770077 is an apocalyptic number.

It is an amenable number.

21770077 is a deficient number, since it is larger than the sum of its proper divisors (3110019).

21770077 is an equidigital number, since it uses as much as digits as its factorization.

21770077 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3110018.

The product of its (nonzero) digits is 4802, while the sum is 31.

The square root of 21770077 is about 4665.8415103816. The cubic root of 21770077 is about 279.2243712699.

Adding to 21770077 its reverse (77007712), we get a palindrome (98777789).

The spelling of 21770077 in words is "twenty-one million, seven hundred seventy thousand, seventy-seven".