20919245 has 16 divisors (see below), whose sum is σ = 26151600. Its totient is φ = 16049664.

The previous prime is 20919229. The next prime is 20919251. The reversal of 20919245 is 54291902.

It can be written as a sum of positive squares in 8 ways, for example, as 244036 + 20675209 = 494^2 + 4547^2 .

It is a cyclic number.

It is not a de Polignac number, because 20919245 - 2⁴ = 20919229 is a prime.

It is a super-2 number, since 2×20919245² = 875229622740050, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12731 + ... + 14279.

It is an arithmetic number, because the mean of its divisors is an integer number (1634475).

Almost surely, 2^20919245 is an apocalyptic number.

It is an amenable number.

20919245 is a deficient number, since it is larger than the sum of its proper divisors (5232355).

20919245 is a wasteful number, since it uses less digits than its factorization.

20919245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1664.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 20919245 is about 4573.7561150547. The cubic root of 20919245 is about 275.5383174472.

The spelling of 20919245 in words is "twenty million, nine hundred nineteen thousand, two hundred forty-five".