21957070 has 8 divisors (see below), whose sum is σ = 39522744. Its totient is φ = 8782824.

The previous prime is 21957053. The next prime is 21957071. The reversal of 21957070 is 7075912.

21957070 is nontrivially palindromic in base 14.

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

It is a super-2 number, since 2×21957070² = 964225845969800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21957071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1097844 + ... + 1097863.

It is an arithmetic number, because the mean of its divisors is an integer number (4940343).

Almost surely, 2^21957070 is an apocalyptic number.

21957070 is a deficient number, since it is larger than the sum of its proper divisors (17565674).

21957070 is a wasteful number, since it uses less digits than its factorization.

21957070 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2195714.

The product of its (nonzero) digits is 4410, while the sum is 31.

The square root of 21957070 is about 4685.8371717336. The cubic root of 21957070 is about 280.0215544631.

The spelling of 21957070 in words is "twenty-one million, nine hundred fifty-seven thousand, seventy".