21863946 has 32 divisors (see below), whose sum is σ = 49573440. Its totient is φ = 6372864.

The previous prime is 21863923. The next prime is 21863951. The reversal of 21863946 is 64936812.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5895 + ... + 8858.

It is an arithmetic number, because the mean of its divisors is an integer number (1549170).

Almost surely, 2^21863946 is an apocalyptic number.

21863946 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21863946 is an abundant number, since it is smaller than the sum of its proper divisors (27709494).

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

21863946 is a wasteful number, since it uses less digits than its factorization.

21863946 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14790.

The product of its digits is 62208, while the sum is 39.

The square root of 21863946 is about 4675.8898618338. The cubic root of 21863946 is about 279.6251190590.

The spelling of 21863946 in words is "twenty-one million, eight hundred sixty-three thousand, nine hundred forty-six".