21001054 has 4 divisors (see below), whose sum is σ = 31501584. Its totient is φ = 10500526.

The previous prime is 21001049. The next prime is 21001081. The reversal of 21001054 is 45010012.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×21001054² = 882088538221832, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5250262 + ... + 5250265.

It is an arithmetic number, because the mean of its divisors is an integer number (7875396).

Almost surely, 2^21001054 is an apocalyptic number.

21001054 is a deficient number, since it is larger than the sum of its proper divisors (10500530).

21001054 is a wasteful number, since it uses less digits than its factorization.

21001054 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10500529.

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 21001054 is about 4582.6906943410. The cubic root of 21001054 is about 275.8970332848.

Adding to 21001054 its reverse (45010012), we get a palindrome (66011066).

The spelling of 21001054 in words is "twenty-one million, one thousand, fifty-four".