51621421515 has 8 divisors (see below), whose sum is σ = 82594274448. Its totient is φ = 27531424800.

The previous prime is 51621421477. The next prime is 51621421541. The reversal of 51621421515 is 51512412615.

It is a happy number.

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

It is not a de Polignac number, because 51621421515 - 2¹³ = 51621413323 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1720714036 + ... + 1720714065.

It is an arithmetic number, because the mean of its divisors is an integer number (10324284306).

Almost surely, 2^51621421515 is an apocalyptic number.

51621421515 is a deficient number, since it is larger than the sum of its proper divisors (30972852933).

51621421515 is a wasteful number, since it uses less digits than its factorization.

51621421515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3441428109.

The product of its digits is 12000, while the sum is 33.

The spelling of 51621421515 in words is "fifty-one billion, six hundred twenty-one million, four hundred twenty-one thousand, five hundred fifteen".