51212091 has 8 divisors (see below), whose sum is σ = 78037504. Its totient is φ = 29264040.

The previous prime is 51212081. The next prime is 51212101. The reversal of 51212091 is 19021215.

It is an interprime number because it is at equal distance from previous prime (51212081) and next prime (51212101).

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

It is not a de Polignac number, because 51212091 - 2⁶ = 51212027 is a prime.

It is a super-4 number, since 4×51212091⁴ (a number of 32 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 2438671 = 51212091 / (5 + 1 + 2 + 1 + 2 + 0 + 9 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51212071) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1219315 + ... + 1219356.

It is an arithmetic number, because the mean of its divisors is an integer number (9754688).

Almost surely, 2^51212091 is an apocalyptic number.

51212091 is a deficient number, since it is larger than the sum of its proper divisors (26825413).

51212091 is a wasteful number, since it uses less digits than its factorization.

51212091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2438681.

The product of its (nonzero) digits is 180, while the sum is 21.

The square root of 51212091 is about 7156.2623624347. The cubic root of 51212091 is about 371.3563343106.

The spelling of 51212091 in words is "fifty-one million, two hundred twelve thousand, ninety-one".