70637821 has 2 divisors, whose sum is σ = 70637822. Its totient is φ = 70637820.

The previous prime is 70637797. The next prime is 70637849. The reversal of 70637821 is 12873607.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 45024100 + 25613721 = 6710^2 + 5061^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-70637821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (70637321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35318910 + 35318911.

It is an arithmetic number, because the mean of its divisors is an integer number (35318911).

Almost surely, 2^70637821 is an apocalyptic number.

It is an amenable number.

70637821 is a deficient number, since it is larger than the sum of its proper divisors (1).

70637821 is an equidigital number, since it uses as much as digits as its factorization.

70637821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14112, while the sum is 34.

The square root of 70637821 is about 8404.6309258646. The cubic root of 70637821 is about 413.3764817223.

It can be divided in two parts, 7063 and 7821, that added together give a square (14884 = 122²).

The spelling of 70637821 in words is "seventy million, six hundred thirty-seven thousand, eight hundred twenty-one".