20471957 has 8 divisors (see below), whose sum is σ = 22372320. Its totient is φ = 18578160.

The previous prime is 20471951. The next prime is 20471963. The reversal of 20471957 is 75917402.

It is an interprime number because it is at equal distance from previous prime (20471951) and next prime (20471963).

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 20471957 - 2²⁴ = 3694741 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 (20471951) 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, 6794 + ... + 9332.

It is an arithmetic number, because the mean of its divisors is an integer number (2796540).

Almost surely, 2^20471957 is an apocalyptic number.

It is an amenable number.

20471957 is a deficient number, since it is larger than the sum of its proper divisors (1900363).

20471957 is a wasteful number, since it uses less digits than its factorization.

20471957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3283.

The product of its (nonzero) digits is 17640, while the sum is 35.

The square root of 20471957 is about 4524.5946779795. The cubic root of 20471957 is about 273.5603307981.

It can be divided in two parts, 2047 and 1957, that added together give a palindrome (4004).

The spelling of 20471957 in words is "twenty million, four hundred seventy-one thousand, nine hundred fifty-seven".