21402142515 has 64 divisors (see below), whose sum is σ = 41115876480. Its totient is φ = 10500226560.

The previous prime is 21402142453. The next prime is 21402142529. The reversal of 21402142515 is 51524120412.

It is a happy number.

21402142515 is a `hidden beast` number, since 2 + 1 + 4 + 0 + 2 + 142 + 515 = 666.

It is not a de Polignac number, because 21402142515 - 2¹¹ = 21402140467 is a prime.

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

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 493405 + ... + 535025.

It is an arithmetic number, because the mean of its divisors is an integer number (642435570).

Almost surely, 2^21402142515 is an apocalyptic number.

21402142515 is a deficient number, since it is larger than the sum of its proper divisors (19713733965).

21402142515 is a wasteful number, since it uses less digits than its factorization.

21402142515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41941 (or 41935 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

Adding to 21402142515 its reverse (51524120412), we get a palindrome (72926262927).

The spelling of 21402142515 in words is "twenty-one billion, four hundred two million, one hundred forty-two thousand, five hundred fifteen".