21973757 has 8 divisors (see below), whose sum is σ = 23759736. Its totient is φ = 20201472.

The previous prime is 21973753. The next prime is 21973781. The reversal of 21973757 is 75737912.

It can be written as a sum of positive squares in 4 ways, for example, as 12859396 + 9114361 = 3586^2 + 3019^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21973757 - 2² = 21973753 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21973753) 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, 53 + ... + 6629.

It is an arithmetic number, because the mean of its divisors is an integer number (2969967).

Almost surely, 2^21973757 is an apocalyptic number.

It is an amenable number.

21973757 is a deficient number, since it is larger than the sum of its proper divisors (1785979).

21973757 is a wasteful number, since it uses less digits than its factorization.

21973757 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6847.

The product of its digits is 92610, while the sum is 41.

The square root of 21973757 is about 4687.6174118629. The cubic root of 21973757 is about 280.0924737077.

It can be divided in two parts, 2197 and 3757, that multiplied together give a square (8254129 = 2873²).

The spelling of 21973757 in words is "twenty-one million, nine hundred seventy-three thousand, seven hundred fifty-seven".