1640696406 has 8 divisors (see below), whose sum is σ = 3281392824. Its totient is φ = 546898800.

The previous prime is 1640696383. The next prime is 1640696423. The reversal of 1640696406 is 6046960461.

It is a sphenic number, since it is the product of 3 distinct primes.

1640696406 is an admirable number.

It is a super-2 number, since 2×1640696406² = 5383769393322633672, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 136724695 + ... + 136724706.

It is an arithmetic number, because the mean of its divisors is an integer number (410174103).

Almost surely, 2^1640696406 is an apocalyptic number.

1640696406 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1640696406 is a wasteful number, since it uses less digits than its factorization.

1640696406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273449406.

The product of its (nonzero) digits is 186624, while the sum is 42.

The square root of 1640696406 is about 40505.5108102589. The cubic root of 1640696406 is about 1179.4406057722.

The spelling of 1640696406 in words is "one billion, six hundred forty million, six hundred ninety-six thousand, four hundred six".