23661820 has 48 divisors (see below), whose sum is σ = 61161408. Its totient is φ = 7488000.

The previous prime is 23661811. The next prime is 23661857. The reversal of 23661820 is 2816632.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4681 + ... + 8320.

It is an arithmetic number, because the mean of its divisors is an integer number (1274196).

Almost surely, 2^23661820 is an apocalyptic number.

23661820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

23661820 is an abundant number, since it is smaller than the sum of its proper divisors (37499588).

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

23661820 is a wasteful number, since it uses less digits than its factorization.

23661820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13030 (or 13028 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 23661820 is about 4864.3416820779. The cubic root of 23661820 is about 287.0886669753.

It can be divided in two parts, 2366 and 1820, that added together give a triangular number (4186 = T₉₁).

The spelling of 23661820 in words is "twenty-three million, six hundred sixty-one thousand, eight hundred twenty".