20185878420 has 36 divisors (see below), whose sum is σ = 61230498420. Its totient is φ = 5382900864.

The previous prime is 20185878409. The next prime is 20185878467. The reversal of 20185878420 is 2487858102.

It is a happy number.

20185878420 is a `hidden beast` number, since 20 + 1 + 8 + 587 + 8 + 42 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 15847284996 + 4338593424 = 125886^2 + 65868^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 56071705 + ... + 56072064.

Almost surely, 2^20185878420 is an apocalyptic number.

20185878420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20185878420 is an abundant number, since it is smaller than the sum of its proper divisors (41044620000).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20185878420 is a wasteful number, since it uses less digits than its factorization.

20185878420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112143784 (or 112143779 counting only the distinct ones).

The product of its (nonzero) digits is 286720, while the sum is 45.

The spelling of 20185878420 in words is "twenty billion, one hundred eighty-five million, eight hundred seventy-eight thousand, four hundred twenty".