21755006 has 16 divisors (see below), whose sum is σ = 40163424. Its totient is φ = 8606304.

The previous prime is 21755003. The next prime is 21755009. The reversal of 21755006 is 60055712.

It is an interprime number because it is at equal distance from previous prime (21755003) and next prime (21755009).

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21755003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59585 + ... + 59948.

It is an arithmetic number, because the mean of its divisors is an integer number (2510214).

Almost surely, 2^21755006 is an apocalyptic number.

21755006 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21755006 is a deficient number, since it is larger than the sum of its proper divisors (18408418).

21755006 is a wasteful number, since it uses less digits than its factorization.

21755006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119555.

The product of its (nonzero) digits is 2100, while the sum is 26.

The square root of 21755006 is about 4664.2261952011. The cubic root of 21755006 is about 279.1599225321.

The spelling of 21755006 in words is "twenty-one million, seven hundred fifty-five thousand, six".