51690949 has 2 divisors, whose sum is σ = 51690950. Its totient is φ = 51690948.

The previous prime is 51690943. The next prime is 51690979. The reversal of 51690949 is 94909615.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48902049 + 2788900 = 6993^2 + 1670^2 .

It is a cyclic number.

It is not a de Polignac number, because 51690949 - 2³ = 51690941 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51690941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25845474 + 25845475.

It is an arithmetic number, because the mean of its divisors is an integer number (25845475).

Almost surely, 2^51690949 is an apocalyptic number.

It is an amenable number.

51690949 is a deficient number, since it is larger than the sum of its proper divisors (1).

51690949 is an equidigital number, since it uses as much as digits as its factorization.

51690949 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 87480, while the sum is 43.

The square root of 51690949 is about 7189.6417852352. The cubic root of 51690949 is about 372.5101995616.

The spelling of 51690949 in words is "fifty-one million, six hundred ninety thousand, nine hundred forty-nine".