20957890 has 8 divisors (see below), whose sum is σ = 37724220. Its totient is φ = 8383152.

The previous prime is 20957869. The next prime is 20957903. The reversal of 20957890 is 9875902.

It can be written as a sum of positive squares in 2 ways, for example, as 17065161 + 3892729 = 4131^2 + 1973^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1047885 + ... + 1047904.

Almost surely, 2^20957890 is an apocalyptic number.

20957890 is a deficient number, since it is larger than the sum of its proper divisors (16766330).

20957890 is a wasteful number, since it uses less digits than its factorization.

20957890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2095796.

The product of its (nonzero) digits is 45360, while the sum is 40.

The square root of 20957890 is about 4577.9788116591. The cubic root of 20957890 is about 275.7078842433.

The spelling of 20957890 in words is "twenty million, nine hundred fifty-seven thousand, eight hundred ninety".