21802641 has 32 divisors (see below), whose sum is σ = 34725888. Its totient is φ = 11905920.

The previous prime is 21802621. The next prime is 21802661. The reversal of 21802641 is 14620812.

It is an interprime number because it is at equal distance from previous prime (21802621) and next prime (21802661).

It is not a de Polignac number, because 21802641 - 2⁷ = 21802513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21802601) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 69501 + ... + 69813.

It is an arithmetic number, because the mean of its divisors is an integer number (1085184).

Almost surely, 2^21802641 is an apocalyptic number.

21802641 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21802641 is a deficient number, since it is larger than the sum of its proper divisors (12923247).

21802641 is a wasteful number, since it uses less digits than its factorization.

21802641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461.

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 21802641 is about 4669.3298234329. The cubic root of 21802641 is about 279.3635245450.

The spelling of 21802641 in words is "twenty-one million, eight hundred two thousand, six hundred forty-one".