21501054 has 24 divisors (see below), whose sum is σ = 46931040. Its totient is φ = 7113888.

The previous prime is 21501031. The next prime is 21501059. The reversal of 21501054 is 45010512.

It is a super-2 number, since 2×21501054² = 924590646221832, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21501059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1894 + ... + 6825.

It is an arithmetic number, because the mean of its divisors is an integer number (1955460).

Almost surely, 2^21501054 is an apocalyptic number.

21501054 is an abundant number, since it is smaller than the sum of its proper divisors (25429986).

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

21501054 is a wasteful number, since it uses less digits than its factorization.

21501054 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8864 (or 8861 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 21501054 is about 4636.9229020979. The cubic root of 21501054 is about 278.0694321339.

Adding to 21501054 its reverse (45010512), we get a palindrome (66511566).

The spelling of 21501054 in words is "twenty-one million, five hundred one thousand, fifty-four".