20357645 has 64 divisors (see below), whose sum is σ = 33730560. Its totient is φ = 11499840.

The previous prime is 20357639. The next prime is 20357657. The reversal of 20357645 is 54675302.

20357645 = T₂₉₉ + T₃₀₀ + ... + T₅₂₉.

20357645 = 161² + 162² + ... + 402².

It is not a de Polignac number, because 20357645 - 2⁴ = 20357629 is a prime.

It is a super-3 number, since 3×20357645³ (a number of 23 digits) contains 333 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 885104 + ... + 885126.

It is an arithmetic number, because the mean of its divisors is an integer number (527040).

Almost surely, 2^20357645 is an apocalyptic number.

It is an amenable number.

20357645 is a deficient number, since it is larger than the sum of its proper divisors (13372915).

20357645 is a wasteful number, since it uses less digits than its factorization.

20357645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87 (or 65 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 32.

The square root of 20357645 is about 4511.9447026753. The cubic root of 20357645 is about 273.0502083541.

The spelling of 20357645 in words is "twenty million, three hundred fifty-seven thousand, six hundred forty-five".