40721251 has 2 divisors, whose sum is σ = 40721252. Its totient is φ = 40721250.

The previous prime is 40721243. The next prime is 40721287. The reversal of 40721251 is 15212704.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 40721251 - 2³ = 40721243 is a prime.

It is not a weakly prime, because it can be changed into another prime (40791251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20360625 + 20360626.

It is an arithmetic number, because the mean of its divisors is an integer number (20360626).

Almost surely, 2^40721251 is an apocalyptic number.

40721251 is a deficient number, since it is larger than the sum of its proper divisors (1).

40721251 is an equidigital number, since it uses as much as digits as its factorization.

40721251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 40721251 is about 6381.3204746353. The cubic root of 40721251 is about 344.0384934164.

Adding to 40721251 its reverse (15212704), we get a palindrome (55933955).

The spelling of 40721251 in words is "forty million, seven hundred twenty-one thousand, two hundred fifty-one".