21101487 has 8 divisors (see below), whose sum is σ = 30693120. Its totient is φ = 12788760.

The previous prime is 21101461. The next prime is 21101503. The reversal of 21101487 is 78410112.

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

It is not a de Polignac number, because 21101487 - 2¹⁰ = 21100463 is a prime.

It is a super-2 number, since 2×21101487² = 890545507222338, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101407) 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, 319687 + ... + 319752.

It is an arithmetic number, because the mean of its divisors is an integer number (3836640).

Almost surely, 2^21101487 is an apocalyptic number.

21101487 is a deficient number, since it is larger than the sum of its proper divisors (9591633).

21101487 is a wasteful number, since it uses less digits than its factorization.

21101487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 639453.

The product of its (nonzero) digits is 448, while the sum is 24.

The square root of 21101487 is about 4593.6354883687. The cubic root of 21101487 is about 276.3361400188.

Adding to 21101487 its reverse (78410112), we get a palindrome (99511599).

The spelling of 21101487 in words is "twenty-one million, one hundred one thousand, four hundred eighty-seven".