21770751 has 8 divisors (see below), whose sum is σ = 30555520. Its totient is φ = 13749912.

The previous prime is 21770747. The next prime is 21770797. The reversal of 21770751 is 15707712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21770751 - 2² = 21770747 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 (21770701) 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, 190915 + ... + 191028.

It is an arithmetic number, because the mean of its divisors is an integer number (3819440).

Almost surely, 2^21770751 is an apocalyptic number.

21770751 is a deficient number, since it is larger than the sum of its proper divisors (8784769).

21770751 is a wasteful number, since it uses less digits than its factorization.

21770751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 381965.

The product of its (nonzero) digits is 3430, while the sum is 30.

The square root of 21770751 is about 4665.9137368794. The cubic root of 21770751 is about 279.2272528289.

The spelling of 21770751 in words is "twenty-one million, seven hundred seventy thousand, seven hundred fifty-one".