21070957 has 8 divisors (see below), whose sum is σ = 21352320. Its totient is φ = 20791680.

The previous prime is 21070949. The next prime is 21070969. The reversal of 21070957 is 75907012.

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 21070957 - 2³ = 21070949 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 (21070937) 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, 30973 + ... + 31645.

It is an arithmetic number, because the mean of its divisors is an integer number (2669040).

Almost surely, 2^21070957 is an apocalyptic number.

It is an amenable number.

21070957 is a deficient number, since it is larger than the sum of its proper divisors (281363).

21070957 is a wasteful number, since it uses less digits than its factorization.

21070957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1043.

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

The square root of 21070957 is about 4590.3112094933. The cubic root of 21070957 is about 276.2028063767.

Adding to 21070957 its reverse (75907012), we get a palindrome (96977969).

The spelling of 21070957 in words is "twenty-one million, seventy thousand, nine hundred fifty-seven".