690772221 has 12 divisors (see below), whose sum is σ = 1005066972. Its totient is φ = 457152576.

The previous prime is 690772213. The next prime is 690772241. The reversal of 690772221 is 122277096.

It can be written as a sum of positive squares in 2 ways, for example, as 570540996 + 120231225 = 23886^2 + 10965^2 .

It is not a de Polignac number, because 690772221 - 2³ = 690772213 is a prime.

It is a super-2 number, since 2×690772221² = 954332522610545682, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (690772241) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 278886 + ... + 281351.

It is an arithmetic number, because the mean of its divisors is an integer number (83755581).

Almost surely, 2^690772221 is an apocalyptic number.

It is an amenable number.

690772221 is a deficient number, since it is larger than the sum of its proper divisors (314294751).

690772221 is a wasteful number, since it uses less digits than its factorization.

690772221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 560380 (or 560377 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 36.

The square root of 690772221 is about 26282.5459383219. The cubic root of 690772221 is about 883.9851202596.

The spelling of 690772221 in words is "six hundred ninety million, seven hundred seventy-two thousand, two hundred twenty-one".