3640185820381 has 16 divisors (see below), whose sum is σ = 3973675903488. Its totient is φ = 3307123825200.

The previous prime is 3640185820319. The next prime is 3640185820393. The reversal of 3640185820381 is 1830285810463.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 3640185820381 - 2⁷ = 3640185820253 is a prime.

It is a super-2 number, since 2×3640185820381² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3640185820301) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 120572770 + ... + 120602956.

It is an arithmetic number, because the mean of its divisors is an integer number (248354743968).

Almost surely, 2^{3640185820381} is an apocalyptic number.

It is an amenable number.

3640185820381 is a deficient number, since it is larger than the sum of its proper divisors (333490083107).

3640185820381 is a wasteful number, since it uses less digits than its factorization.

3640185820381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36912.

The product of its (nonzero) digits is 1105920, while the sum is 49.

The spelling of 3640185820381 in words is "three trillion, six hundred forty billion, one hundred eighty-five million, eight hundred twenty thousand, three hundred eighty-one".