21770642 has 16 divisors (see below), whose sum is σ = 35383392. Its totient is φ = 10006080.

The previous prime is 21770641. The next prime is 21770653. The reversal of 21770642 is 24607712.

It is not an unprimeable number, because it can be changed into a prime (21770641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5984 + ... + 8907.

It is an arithmetic number, because the mean of its divisors is an integer number (2211462).

Almost surely, 2^21770642 is an apocalyptic number.

21770642 is a deficient number, since it is larger than the sum of its proper divisors (13612750).

21770642 is a wasteful number, since it uses less digits than its factorization.

21770642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14953.

The product of its (nonzero) digits is 4704, while the sum is 29.

The square root of 21770642 is about 4665.9020564088. The cubic root of 21770642 is about 279.2267868241.

The spelling of 21770642 in words is "twenty-one million, seven hundred seventy thousand, six hundred forty-two".