21102477 has 16 divisors (see below), whose sum is σ = 32030208. Its totient is φ = 12232880.

The previous prime is 21102467. The next prime is 21102481. The reversal of 21102477 is 77420112.

It is not a de Polignac number, because 21102477 - 2¹² = 21098381 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102467) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13143 + ... + 14660.

It is an arithmetic number, because the mean of its divisors is an integer number (2001888).

Almost surely, 2^21102477 is an apocalyptic number.

It is an amenable number.

21102477 is a deficient number, since it is larger than the sum of its proper divisors (10927731).

21102477 is a wasteful number, since it uses less digits than its factorization.

21102477 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27840.

The product of its (nonzero) digits is 784, while the sum is 24.

The square root of 21102477 is about 4593.7432448930. The cubic root of 21102477 is about 276.3404614915.

Adding to 21102477 its reverse (77420112), we get a palindrome (98522589).

The spelling of 21102477 in words is "twenty-one million, one hundred two thousand, four hundred seventy-seven".