51691001 has 4 divisors (see below), whose sum is σ = 54411600. Its totient is φ = 48970404.

The previous prime is 51690983. The next prime is 51691019. The reversal of 51691001 is 10019615.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (51690983) and next prime (51691019).

It is a cyclic number.

It is not a de Polignac number, because 51691001 - 2⁶ = 51690937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51691061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1360271 + ... + 1360308.

It is an arithmetic number, because the mean of its divisors is an integer number (13602900).

Almost surely, 2^51691001 is an apocalyptic number.

It is an amenable number.

51691001 is a deficient number, since it is larger than the sum of its proper divisors (2720599).

51691001 is a wasteful number, since it uses less digits than its factorization.

51691001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2720598.

The product of its (nonzero) digits is 270, while the sum is 23.

The square root of 51691001 is about 7189.6454015480. The cubic root of 51691001 is about 372.5103244740.

The spelling of 51691001 in words is "fifty-one million, six hundred ninety-one thousand, one".