51621506 has 8 divisors (see below), whose sum is σ = 77635584. Its totient is φ = 25742980.

The previous prime is 51621491. The next prime is 51621511. The reversal of 51621506 is 60512615.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32930 + ... + 34461.

It is an arithmetic number, because the mean of its divisors is an integer number (9704448).

Almost surely, 2^51621506 is an apocalyptic number.

51621506 is a deficient number, since it is larger than the sum of its proper divisors (26014078).

51621506 is a wasteful number, since it uses less digits than its factorization.

51621506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67776.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 51621506 is about 7184.8107838690. The cubic root of 51621506 is about 372.3433114250.

It can be divided in two parts, 516 and 21506, that added together give a palindrome (22022).

The spelling of 51621506 in words is "fifty-one million, six hundred twenty-one thousand, five hundred six".