20948557 has 4 divisors (see below), whose sum is σ = 23941216. Its totient is φ = 17955900.

The previous prime is 20948537. The next prime is 20948563. The reversal of 20948557 is 75584902.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20948557 - 2⁷ = 20948429 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 (20948537) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1496319 + ... + 1496332.

It is an arithmetic number, because the mean of its divisors is an integer number (5985304).

Almost surely, 2^20948557 is an apocalyptic number.

It is an amenable number.

20948557 is a deficient number, since it is larger than the sum of its proper divisors (2992659).

20948557 is an equidigital number, since it uses as much as digits as its factorization.

20948557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2992658.

The product of its (nonzero) digits is 100800, while the sum is 40.

The square root of 20948557 is about 4576.9593618471. The cubic root of 20948557 is about 275.6669519461. Note that the first 3 decimals are identical.

The spelling of 20948557 in words is "twenty million, nine hundred forty-eight thousand, five hundred fifty-seven".