690867621 has 6 divisors (see below), whose sum is σ = 997919910. Its totient is φ = 460578408.

The previous prime is 690867613. The next prime is 690867623. The reversal of 690867621 is 126768096.

It can be written as a sum of positive squares in only one way, i.e., 411643521 + 279224100 = 20289^2 + 16710^2 .

It is not a de Polignac number, because 690867621 - 2³ = 690867613 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (690867623) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 38381526 + ... + 38381543.

It is an arithmetic number, because the mean of its divisors is an integer number (166319985).

Almost surely, 2^690867621 is an apocalyptic number.

It is an amenable number.

690867621 is a deficient number, since it is larger than the sum of its proper divisors (307052289).

690867621 is a wasteful number, since it uses less digits than its factorization.

690867621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76763075 (or 76763072 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 690867621 is about 26284.3607683352. The cubic root of 690867621 is about 884.0258130263.

It can be divided in two parts, 6908 and 67621, that added together give a square (74529 = 273²).

The spelling of 690867621 in words is "six hundred ninety million, eight hundred sixty-seven thousand, six hundred twenty-one".