21057722 has 16 divisors (see below), whose sum is σ = 36365760. Its totient is φ = 8958048.

The previous prime is 21057709. The next prime is 21057727. The reversal of 21057722 is 22775012.

It is a junction number, because it is equal to n+sod(n) for n = 21057691 and 21057700.

It is not an unprimeable number, because it can be changed into a prime (21057727) 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, 3572 + ... + 7407.

It is an arithmetic number, because the mean of its divisors is an integer number (2272860).

Almost surely, 2^21057722 is an apocalyptic number.

21057722 is a deficient number, since it is larger than the sum of its proper divisors (15308038).

21057722 is a wasteful number, since it uses less digits than its factorization.

21057722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11125.

The product of its (nonzero) digits is 1960, while the sum is 26.

The square root of 21057722 is about 4588.8693596571. The cubic root of 21057722 is about 276.1449651536.

The spelling of 21057722 in words is "twenty-one million, fifty-seven thousand, seven hundred twenty-two".