20961457 has 8 divisors (see below), whose sum is σ = 22964832. Its totient is φ = 18974400.

The previous prime is 20961443. The next prime is 20961467. The reversal of 20961457 is 75416902.

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 20961457 - 2⁷ = 20961329 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20961467) 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, 1303 + ... + 6604.

It is an arithmetic number, because the mean of its divisors is an integer number (2870604).

Almost surely, 2^20961457 is an apocalyptic number.

It is an amenable number.

20961457 is a deficient number, since it is larger than the sum of its proper divisors (2003375).

20961457 is a wasteful number, since it uses less digits than its factorization.

20961457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8159.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 20961457 is about 4578.3683774900. The cubic root of 20961457 is about 275.7235250391.

Subtracting 20961457 from its reverse (75416902), we obtain a palindrome (54455445).

It can be divided in two parts, 2096 and 1457, that added together give a palindrome (3553).

The spelling of 20961457 in words is "twenty million, nine hundred sixty-one thousand, four hundred fifty-seven".