21006102465 has 32 divisors (see below), whose sum is σ = 37977148800. Its totient is φ = 11013364800.

The previous prime is 21006102461. The next prime is 21006102493. The reversal of 21006102465 is 56420160012.

21006102465 is a `hidden beast` number, since 2 + 1 + 0 + 0 + 610 + 2 + 46 + 5 = 666.

It is not a de Polignac number, because 21006102465 - 2² = 21006102461 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21006102461) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1310686 + ... + 1326615.

It is an arithmetic number, because the mean of its divisors is an integer number (1186785900).

Almost surely, 2^21006102465 is an apocalyptic number.

It is an amenable number.

21006102465 is a deficient number, since it is larger than the sum of its proper divisors (16971046335).

21006102465 is a wasteful number, since it uses less digits than its factorization.

21006102465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2637374 (or 2637368 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

Adding to 21006102465 its reverse (56420160012), we get a palindrome (77426262477).

The spelling of 21006102465 in words is "twenty-one billion, six million, one hundred two thousand, four hundred sixty-five".