70821081 has 32 divisors (see below), whose sum is σ = 109117440. Its totient is φ = 45349200.

The previous prime is 70821073. The next prime is 70821097. The reversal of 70821081 is 18012807.

It is not a de Polignac number, because 70821081 - 2³ = 70821073 is a prime.

It is a super-2 number, since 2×70821081² = 10031251028017122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (70821581) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 159646 + ... + 160088.

It is an arithmetic number, because the mean of its divisors is an integer number (3409920).

Almost surely, 2^70821081 is an apocalyptic number.

It is an amenable number.

70821081 is a deficient number, since it is larger than the sum of its proper divisors (38296359).

70821081 is a wasteful number, since it uses less digits than its factorization.

70821081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 674 (or 668 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 27.

The square root of 70821081 is about 8415.5261867574. The cubic root of 70821081 is about 413.7336556128.

Adding to 70821081 its reverse (18012807), we get a palindrome (88833888).

The spelling of 70821081 in words is "seventy million, eight hundred twenty-one thousand, eighty-one".