101861820 has 48 divisors (see below), whose sum is σ = 316905120. Its totient is φ = 27163008.

The previous prime is 101861819. The next prime is 101861821. The reversal of 101861820 is 28168101.

101861820 is a `hidden beast` number, since 10 + 18 + 618 + 20 = 666.

It is an interprime number because it is at equal distance from previous prime (101861819) and next prime (101861821).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (101861821) 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, 93777 + ... + 94856.

It is an arithmetic number, because the mean of its divisors is an integer number (6602190).

Almost surely, 2^101861820 is an apocalyptic number.

101861820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

101861820 is an abundant number, since it is smaller than the sum of its proper divisors (215043300).

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

101861820 is a wasteful number, since it uses less digits than its factorization.

101861820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188651 (or 188643 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 27.

The square root of 101861820 is about 10092.6616905552. The cubic root of 101861820 is about 467.0217897812.

The spelling of 101861820 in words is "one hundred one million, eight hundred sixty-one thousand, eight hundred twenty".