51215101402 has 4 divisors (see below), whose sum is σ = 76822652106. Its totient is φ = 25607550700.

The previous prime is 51215101387. The next prime is 51215101411. The reversal of 51215101402 is 20410151215.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 49160201841 + 2054899561 = 221721^2 + 45331^2 .

It is a super-2 number, since 2×51215101402² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12803775349 + ... + 12803775352.

Almost surely, 2^51215101402 is an apocalyptic number.

51215101402 is a deficient number, since it is larger than the sum of its proper divisors (25607550704).

51215101402 is a wasteful number, since it uses less digits than its factorization.

51215101402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25607550703.

The product of its (nonzero) digits is 400, while the sum is 22.

Adding to 51215101402 its reverse (20410151215), we get a palindrome (71625252617).

The spelling of 51215101402 in words is "fifty-one billion, two hundred fifteen million, one hundred one thousand, four hundred two".