21770790 has 32 divisors (see below), whose sum is σ = 52970976. Its totient is φ = 5725440.

The previous prime is 21770747. The next prime is 21770797. The reversal of 21770790 is 9707712.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21770797) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2781 + ... + 7160.

It is an arithmetic number, because the mean of its divisors is an integer number (1655343).

Almost surely, 2^21770790 is an apocalyptic number.

21770790 is an abundant number, since it is smaller than the sum of its proper divisors (31200186).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21770790 is a wasteful number, since it uses less digits than its factorization.

21770790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10024.

The product of its (nonzero) digits is 6174, while the sum is 33.

The square root of 21770790 is about 4665.9179161233. The cubic root of 21770790 is about 279.2274195642.

The spelling of 21770790 in words is "twenty-one million, seven hundred seventy thousand, seven hundred ninety".