21055151 has 8 divisors (see below), whose sum is σ = 23103360. Its totient is φ = 19068192.

The previous prime is 21055147. The next prime is 21055207. The reversal of 21055151 is 15155012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21055151 - 2² = 21055147 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21055141) 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, 14591 + ... + 15968.

It is an arithmetic number, because the mean of its divisors is an integer number (2887920).

Almost surely, 2^21055151 is an apocalyptic number.

21055151 is a deficient number, since it is larger than the sum of its proper divisors (2048209).

21055151 is a wasteful number, since it uses less digits than its factorization.

21055151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30625.

The product of its (nonzero) digits is 250, while the sum is 20.

The square root of 21055151 is about 4588.5892167419. The cubic root of 21055151 is about 276.1337262424.

The spelling of 21055151 in words is "twenty-one million, fifty-five thousand, one hundred fifty-one".